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
186 * _shift_data_right_pages
187 * @pages: vector of pages containing both the source and dest memory area.
188 * @pgto_base: page vector address of destination
189 * @pgfrom_base: page vector address of source
190 * @len: number of bytes to copy
192 * Note: the addresses pgto_base and pgfrom_base are both calculated in
194 * if a memory area starts at byte 'base' in page 'pages[i]',
195 * then its address is given as (i << PAGE_CACHE_SHIFT) + base
196 * Also note: pgfrom_base must be < pgto_base, but the memory areas
197 * they point to may overlap.
200 _shift_data_right_pages(struct page
**pages
, size_t pgto_base
,
201 size_t pgfrom_base
, size_t len
)
203 struct page
**pgfrom
, **pgto
;
207 BUG_ON(pgto_base
<= pgfrom_base
);
212 pgto
= pages
+ (pgto_base
>> PAGE_CACHE_SHIFT
);
213 pgfrom
= pages
+ (pgfrom_base
>> PAGE_CACHE_SHIFT
);
215 pgto_base
&= ~PAGE_CACHE_MASK
;
216 pgfrom_base
&= ~PAGE_CACHE_MASK
;
219 /* Are any pointers crossing a page boundary? */
220 if (pgto_base
== 0) {
221 pgto_base
= PAGE_CACHE_SIZE
;
224 if (pgfrom_base
== 0) {
225 pgfrom_base
= PAGE_CACHE_SIZE
;
230 if (copy
> pgto_base
)
232 if (copy
> pgfrom_base
)
237 vto
= kmap_atomic(*pgto
);
238 vfrom
= kmap_atomic(*pgfrom
);
239 memmove(vto
+ pgto_base
, vfrom
+ pgfrom_base
, copy
);
240 flush_dcache_page(*pgto
);
241 kunmap_atomic(vfrom
);
244 } while ((len
-= copy
) != 0);
249 * @pages: array of pages
250 * @pgbase: page vector address of destination
251 * @p: pointer to source data
254 * Copies data from an arbitrary memory location into an array of pages
255 * The copy is assumed to be non-overlapping.
258 _copy_to_pages(struct page
**pages
, size_t pgbase
, const char *p
, size_t len
)
264 pgto
= pages
+ (pgbase
>> PAGE_CACHE_SHIFT
);
265 pgbase
&= ~PAGE_CACHE_MASK
;
268 copy
= PAGE_CACHE_SIZE
- pgbase
;
272 vto
= kmap_atomic(*pgto
);
273 memcpy(vto
+ pgbase
, p
, copy
);
281 if (pgbase
== PAGE_CACHE_SIZE
) {
282 flush_dcache_page(*pgto
);
288 flush_dcache_page(*pgto
);
293 * @p: pointer to destination
294 * @pages: array of pages
295 * @pgbase: offset of source data
298 * Copies data into an arbitrary memory location from an array of pages
299 * The copy is assumed to be non-overlapping.
302 _copy_from_pages(char *p
, struct page
**pages
, size_t pgbase
, size_t len
)
304 struct page
**pgfrom
;
308 pgfrom
= pages
+ (pgbase
>> PAGE_CACHE_SHIFT
);
309 pgbase
&= ~PAGE_CACHE_MASK
;
312 copy
= PAGE_CACHE_SIZE
- pgbase
;
316 vfrom
= kmap_atomic(*pgfrom
);
317 memcpy(p
, vfrom
+ pgbase
, copy
);
318 kunmap_atomic(vfrom
);
321 if (pgbase
== PAGE_CACHE_SIZE
) {
327 } while ((len
-= copy
) != 0);
329 EXPORT_SYMBOL_GPL(_copy_from_pages
);
334 * @len: bytes to remove from buf->head[0]
336 * Shrinks XDR buffer's header kvec buf->head[0] by
337 * 'len' bytes. The extra data is not lost, but is instead
338 * moved into the inlined pages and/or the tail.
341 xdr_shrink_bufhead(struct xdr_buf
*buf
, size_t len
)
343 struct kvec
*head
, *tail
;
345 unsigned int pglen
= buf
->page_len
;
349 BUG_ON (len
> head
->iov_len
);
351 /* Shift the tail first */
352 if (tail
->iov_len
!= 0) {
353 if (tail
->iov_len
> len
) {
354 copy
= tail
->iov_len
- len
;
355 memmove((char *)tail
->iov_base
+ len
,
356 tail
->iov_base
, copy
);
358 /* Copy from the inlined pages into the tail */
363 if (offs
>= tail
->iov_len
)
365 else if (copy
> tail
->iov_len
- offs
)
366 copy
= tail
->iov_len
- offs
;
368 _copy_from_pages((char *)tail
->iov_base
+ offs
,
370 buf
->page_base
+ pglen
+ offs
- len
,
372 /* Do we also need to copy data from the head into the tail ? */
374 offs
= copy
= len
- pglen
;
375 if (copy
> tail
->iov_len
)
376 copy
= tail
->iov_len
;
377 memcpy(tail
->iov_base
,
378 (char *)head
->iov_base
+
379 head
->iov_len
- offs
,
383 /* Now handle pages */
386 _shift_data_right_pages(buf
->pages
,
387 buf
->page_base
+ len
,
393 _copy_to_pages(buf
->pages
, buf
->page_base
,
394 (char *)head
->iov_base
+ head
->iov_len
- len
,
397 head
->iov_len
-= len
;
399 /* Have we truncated the message? */
400 if (buf
->len
> buf
->buflen
)
401 buf
->len
= buf
->buflen
;
407 * @len: bytes to remove from buf->pages
409 * Shrinks XDR buffer's page array buf->pages by
410 * 'len' bytes. The extra data is not lost, but is instead
411 * moved into the tail.
414 xdr_shrink_pagelen(struct xdr_buf
*buf
, size_t len
)
418 unsigned int pglen
= buf
->page_len
;
419 unsigned int tailbuf_len
;
422 BUG_ON (len
> pglen
);
424 tailbuf_len
= buf
->buflen
- buf
->head
->iov_len
- buf
->page_len
;
426 /* Shift the tail first */
427 if (tailbuf_len
!= 0) {
428 unsigned int free_space
= tailbuf_len
- tail
->iov_len
;
430 if (len
< free_space
)
432 tail
->iov_len
+= free_space
;
435 if (tail
->iov_len
> len
) {
436 char *p
= (char *)tail
->iov_base
+ len
;
437 memmove(p
, tail
->iov_base
, tail
->iov_len
- len
);
439 copy
= tail
->iov_len
;
440 /* Copy from the inlined pages into the tail */
441 _copy_from_pages((char *)tail
->iov_base
,
442 buf
->pages
, buf
->page_base
+ pglen
- len
,
445 buf
->page_len
-= len
;
447 /* Have we truncated the message? */
448 if (buf
->len
> buf
->buflen
)
449 buf
->len
= buf
->buflen
;
453 xdr_shift_buf(struct xdr_buf
*buf
, size_t len
)
455 xdr_shrink_bufhead(buf
, len
);
457 EXPORT_SYMBOL_GPL(xdr_shift_buf
);
460 * xdr_init_encode - Initialize a struct xdr_stream for sending data.
461 * @xdr: pointer to xdr_stream struct
462 * @buf: pointer to XDR buffer in which to encode data
463 * @p: current pointer inside XDR buffer
465 * Note: at the moment the RPC client only passes the length of our
466 * scratch buffer in the xdr_buf's header kvec. Previously this
467 * meant we needed to call xdr_adjust_iovec() after encoding the
468 * data. With the new scheme, the xdr_stream manages the details
469 * of the buffer length, and takes care of adjusting the kvec
472 void xdr_init_encode(struct xdr_stream
*xdr
, struct xdr_buf
*buf
, __be32
*p
)
474 struct kvec
*iov
= buf
->head
;
475 int scratch_len
= buf
->buflen
- buf
->page_len
- buf
->tail
[0].iov_len
;
477 BUG_ON(scratch_len
< 0);
480 xdr
->p
= (__be32
*)((char *)iov
->iov_base
+ iov
->iov_len
);
481 xdr
->end
= (__be32
*)((char *)iov
->iov_base
+ scratch_len
);
482 BUG_ON(iov
->iov_len
> scratch_len
);
484 if (p
!= xdr
->p
&& p
!= NULL
) {
487 BUG_ON(p
< xdr
->p
|| p
> xdr
->end
);
488 len
= (char *)p
- (char *)xdr
->p
;
494 EXPORT_SYMBOL_GPL(xdr_init_encode
);
497 * xdr_reserve_space - Reserve buffer space for sending
498 * @xdr: pointer to xdr_stream
499 * @nbytes: number of bytes to reserve
501 * Checks that we have enough buffer space to encode 'nbytes' more
502 * bytes of data. If so, update the total xdr_buf length, and
503 * adjust the length of the current kvec.
505 __be32
* xdr_reserve_space(struct xdr_stream
*xdr
, size_t nbytes
)
510 /* align nbytes on the next 32-bit boundary */
513 q
= p
+ (nbytes
>> 2);
514 if (unlikely(q
> xdr
->end
|| q
< p
))
517 xdr
->iov
->iov_len
+= nbytes
;
518 xdr
->buf
->len
+= nbytes
;
521 EXPORT_SYMBOL_GPL(xdr_reserve_space
);
524 * xdr_write_pages - Insert a list of pages into an XDR buffer for sending
525 * @xdr: pointer to xdr_stream
526 * @pages: list of pages
527 * @base: offset of first byte
528 * @len: length of data in bytes
531 void xdr_write_pages(struct xdr_stream
*xdr
, struct page
**pages
, unsigned int base
,
534 struct xdr_buf
*buf
= xdr
->buf
;
535 struct kvec
*iov
= buf
->tail
;
537 buf
->page_base
= base
;
540 iov
->iov_base
= (char *)xdr
->p
;
545 unsigned int pad
= 4 - (len
& 3);
547 BUG_ON(xdr
->p
>= xdr
->end
);
548 iov
->iov_base
= (char *)xdr
->p
+ (len
& 3);
556 EXPORT_SYMBOL_GPL(xdr_write_pages
);
558 static void xdr_set_iov(struct xdr_stream
*xdr
, struct kvec
*iov
,
559 __be32
*p
, unsigned int len
)
561 if (len
> iov
->iov_len
)
564 p
= (__be32
*)iov
->iov_base
;
566 xdr
->end
= (__be32
*)(iov
->iov_base
+ len
);
568 xdr
->page_ptr
= NULL
;
571 static int xdr_set_page_base(struct xdr_stream
*xdr
,
572 unsigned int base
, unsigned int len
)
580 maxlen
= xdr
->buf
->page_len
;
587 base
+= xdr
->buf
->page_base
;
589 pgnr
= base
>> PAGE_SHIFT
;
590 xdr
->page_ptr
= &xdr
->buf
->pages
[pgnr
];
591 kaddr
= page_address(*xdr
->page_ptr
);
593 pgoff
= base
& ~PAGE_MASK
;
594 xdr
->p
= (__be32
*)(kaddr
+ pgoff
);
597 if (pgend
> PAGE_SIZE
)
599 xdr
->end
= (__be32
*)(kaddr
+ pgend
);
604 static void xdr_set_next_page(struct xdr_stream
*xdr
)
606 unsigned int newbase
;
608 newbase
= (1 + xdr
->page_ptr
- xdr
->buf
->pages
) << PAGE_SHIFT
;
609 newbase
-= xdr
->buf
->page_base
;
611 if (xdr_set_page_base(xdr
, newbase
, PAGE_SIZE
) < 0)
612 xdr_set_iov(xdr
, xdr
->buf
->tail
, NULL
, xdr
->buf
->len
);
615 static bool xdr_set_next_buffer(struct xdr_stream
*xdr
)
617 if (xdr
->page_ptr
!= NULL
)
618 xdr_set_next_page(xdr
);
619 else if (xdr
->iov
== xdr
->buf
->head
) {
620 if (xdr_set_page_base(xdr
, 0, PAGE_SIZE
) < 0)
621 xdr_set_iov(xdr
, xdr
->buf
->tail
, NULL
, xdr
->buf
->len
);
623 return xdr
->p
!= xdr
->end
;
627 * xdr_init_decode - Initialize an xdr_stream for decoding data.
628 * @xdr: pointer to xdr_stream struct
629 * @buf: pointer to XDR buffer from which to decode data
630 * @p: current pointer inside XDR buffer
632 void xdr_init_decode(struct xdr_stream
*xdr
, struct xdr_buf
*buf
, __be32
*p
)
635 xdr
->scratch
.iov_base
= NULL
;
636 xdr
->scratch
.iov_len
= 0;
637 if (buf
->head
[0].iov_len
!= 0)
638 xdr_set_iov(xdr
, buf
->head
, p
, buf
->len
);
639 else if (buf
->page_len
!= 0)
640 xdr_set_page_base(xdr
, 0, buf
->len
);
642 EXPORT_SYMBOL_GPL(xdr_init_decode
);
645 * xdr_init_decode - Initialize an xdr_stream for decoding data.
646 * @xdr: pointer to xdr_stream struct
647 * @buf: pointer to XDR buffer from which to decode data
648 * @pages: list of pages to decode into
649 * @len: length in bytes of buffer in pages
651 void xdr_init_decode_pages(struct xdr_stream
*xdr
, struct xdr_buf
*buf
,
652 struct page
**pages
, unsigned int len
)
654 memset(buf
, 0, sizeof(*buf
));
659 xdr_init_decode(xdr
, buf
, NULL
);
661 EXPORT_SYMBOL_GPL(xdr_init_decode_pages
);
663 static __be32
* __xdr_inline_decode(struct xdr_stream
*xdr
, size_t nbytes
)
666 __be32
*q
= p
+ XDR_QUADLEN(nbytes
);
668 if (unlikely(q
> xdr
->end
|| q
< p
))
675 * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
676 * @xdr: pointer to xdr_stream struct
677 * @buf: pointer to an empty buffer
678 * @buflen: size of 'buf'
680 * The scratch buffer is used when decoding from an array of pages.
681 * If an xdr_inline_decode() call spans across page boundaries, then
682 * we copy the data into the scratch buffer in order to allow linear
685 void xdr_set_scratch_buffer(struct xdr_stream
*xdr
, void *buf
, size_t buflen
)
687 xdr
->scratch
.iov_base
= buf
;
688 xdr
->scratch
.iov_len
= buflen
;
690 EXPORT_SYMBOL_GPL(xdr_set_scratch_buffer
);
692 static __be32
*xdr_copy_to_scratch(struct xdr_stream
*xdr
, size_t nbytes
)
695 void *cpdest
= xdr
->scratch
.iov_base
;
696 size_t cplen
= (char *)xdr
->end
- (char *)xdr
->p
;
698 if (nbytes
> xdr
->scratch
.iov_len
)
700 memcpy(cpdest
, xdr
->p
, cplen
);
703 if (!xdr_set_next_buffer(xdr
))
705 p
= __xdr_inline_decode(xdr
, nbytes
);
708 memcpy(cpdest
, p
, nbytes
);
709 return xdr
->scratch
.iov_base
;
713 * xdr_inline_decode - Retrieve XDR data to decode
714 * @xdr: pointer to xdr_stream struct
715 * @nbytes: number of bytes of data to decode
717 * Check if the input buffer is long enough to enable us to decode
718 * 'nbytes' more bytes of data starting at the current position.
719 * If so return the current pointer, then update the current
722 __be32
* xdr_inline_decode(struct xdr_stream
*xdr
, size_t nbytes
)
728 if (xdr
->p
== xdr
->end
&& !xdr_set_next_buffer(xdr
))
730 p
= __xdr_inline_decode(xdr
, nbytes
);
733 return xdr_copy_to_scratch(xdr
, nbytes
);
735 EXPORT_SYMBOL_GPL(xdr_inline_decode
);
738 * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position
739 * @xdr: pointer to xdr_stream struct
740 * @len: number of bytes of page data
742 * Moves data beyond the current pointer position from the XDR head[] buffer
743 * into the page list. Any data that lies beyond current position + "len"
744 * bytes is moved into the XDR tail[].
746 void xdr_read_pages(struct xdr_stream
*xdr
, unsigned int len
)
748 struct xdr_buf
*buf
= xdr
->buf
;
754 /* Realign pages to current pointer position */
756 shift
= iov
->iov_len
+ (char *)iov
->iov_base
- (char *)xdr
->p
;
758 xdr_shrink_bufhead(buf
, shift
);
760 /* Truncate page data and move it into the tail */
761 if (buf
->page_len
> len
)
762 xdr_shrink_pagelen(buf
, buf
->page_len
- len
);
763 padding
= (XDR_QUADLEN(len
) << 2) - len
;
764 xdr
->iov
= iov
= buf
->tail
;
765 /* Compute remaining message length. */
767 shift
= buf
->buflen
- buf
->len
;
773 * Position current pointer at beginning of tail, and
774 * set remaining message length.
776 xdr
->p
= (__be32
*)((char *)iov
->iov_base
+ padding
);
777 xdr
->end
= (__be32
*)((char *)iov
->iov_base
+ end
);
779 EXPORT_SYMBOL_GPL(xdr_read_pages
);
782 * xdr_enter_page - decode data from the XDR page
783 * @xdr: pointer to xdr_stream struct
784 * @len: number of bytes of page data
786 * Moves data beyond the current pointer position from the XDR head[] buffer
787 * into the page list. Any data that lies beyond current position + "len"
788 * bytes is moved into the XDR tail[]. The current pointer is then
789 * repositioned at the beginning of the first XDR page.
791 void xdr_enter_page(struct xdr_stream
*xdr
, unsigned int len
)
793 xdr_read_pages(xdr
, len
);
795 * Position current pointer at beginning of tail, and
796 * set remaining message length.
798 xdr_set_page_base(xdr
, 0, len
);
800 EXPORT_SYMBOL_GPL(xdr_enter_page
);
802 static struct kvec empty_iov
= {.iov_base
= NULL
, .iov_len
= 0};
805 xdr_buf_from_iov(struct kvec
*iov
, struct xdr_buf
*buf
)
808 buf
->tail
[0] = empty_iov
;
810 buf
->buflen
= buf
->len
= iov
->iov_len
;
812 EXPORT_SYMBOL_GPL(xdr_buf_from_iov
);
814 /* Sets subbuf to the portion of buf of length len beginning base bytes
815 * from the start of buf. Returns -1 if base of length are out of bounds. */
817 xdr_buf_subsegment(struct xdr_buf
*buf
, struct xdr_buf
*subbuf
,
818 unsigned int base
, unsigned int len
)
820 subbuf
->buflen
= subbuf
->len
= len
;
821 if (base
< buf
->head
[0].iov_len
) {
822 subbuf
->head
[0].iov_base
= buf
->head
[0].iov_base
+ base
;
823 subbuf
->head
[0].iov_len
= min_t(unsigned int, len
,
824 buf
->head
[0].iov_len
- base
);
825 len
-= subbuf
->head
[0].iov_len
;
828 subbuf
->head
[0].iov_base
= NULL
;
829 subbuf
->head
[0].iov_len
= 0;
830 base
-= buf
->head
[0].iov_len
;
833 if (base
< buf
->page_len
) {
834 subbuf
->page_len
= min(buf
->page_len
- base
, len
);
835 base
+= buf
->page_base
;
836 subbuf
->page_base
= base
& ~PAGE_CACHE_MASK
;
837 subbuf
->pages
= &buf
->pages
[base
>> PAGE_CACHE_SHIFT
];
838 len
-= subbuf
->page_len
;
841 base
-= buf
->page_len
;
842 subbuf
->page_len
= 0;
845 if (base
< buf
->tail
[0].iov_len
) {
846 subbuf
->tail
[0].iov_base
= buf
->tail
[0].iov_base
+ base
;
847 subbuf
->tail
[0].iov_len
= min_t(unsigned int, len
,
848 buf
->tail
[0].iov_len
- base
);
849 len
-= subbuf
->tail
[0].iov_len
;
852 subbuf
->tail
[0].iov_base
= NULL
;
853 subbuf
->tail
[0].iov_len
= 0;
854 base
-= buf
->tail
[0].iov_len
;
861 EXPORT_SYMBOL_GPL(xdr_buf_subsegment
);
863 static void __read_bytes_from_xdr_buf(struct xdr_buf
*subbuf
, void *obj
, unsigned int len
)
865 unsigned int this_len
;
867 this_len
= min_t(unsigned int, len
, subbuf
->head
[0].iov_len
);
868 memcpy(obj
, subbuf
->head
[0].iov_base
, this_len
);
871 this_len
= min_t(unsigned int, len
, subbuf
->page_len
);
873 _copy_from_pages(obj
, subbuf
->pages
, subbuf
->page_base
, this_len
);
876 this_len
= min_t(unsigned int, len
, subbuf
->tail
[0].iov_len
);
877 memcpy(obj
, subbuf
->tail
[0].iov_base
, this_len
);
880 /* obj is assumed to point to allocated memory of size at least len: */
881 int read_bytes_from_xdr_buf(struct xdr_buf
*buf
, unsigned int base
, void *obj
, unsigned int len
)
883 struct xdr_buf subbuf
;
886 status
= xdr_buf_subsegment(buf
, &subbuf
, base
, len
);
889 __read_bytes_from_xdr_buf(&subbuf
, obj
, len
);
892 EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf
);
894 static void __write_bytes_to_xdr_buf(struct xdr_buf
*subbuf
, void *obj
, unsigned int len
)
896 unsigned int this_len
;
898 this_len
= min_t(unsigned int, len
, subbuf
->head
[0].iov_len
);
899 memcpy(subbuf
->head
[0].iov_base
, obj
, this_len
);
902 this_len
= min_t(unsigned int, len
, subbuf
->page_len
);
904 _copy_to_pages(subbuf
->pages
, subbuf
->page_base
, obj
, this_len
);
907 this_len
= min_t(unsigned int, len
, subbuf
->tail
[0].iov_len
);
908 memcpy(subbuf
->tail
[0].iov_base
, obj
, this_len
);
911 /* obj is assumed to point to allocated memory of size at least len: */
912 int write_bytes_to_xdr_buf(struct xdr_buf
*buf
, unsigned int base
, void *obj
, unsigned int len
)
914 struct xdr_buf subbuf
;
917 status
= xdr_buf_subsegment(buf
, &subbuf
, base
, len
);
920 __write_bytes_to_xdr_buf(&subbuf
, obj
, len
);
923 EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf
);
926 xdr_decode_word(struct xdr_buf
*buf
, unsigned int base
, u32
*obj
)
931 status
= read_bytes_from_xdr_buf(buf
, base
, &raw
, sizeof(*obj
));
934 *obj
= be32_to_cpu(raw
);
937 EXPORT_SYMBOL_GPL(xdr_decode_word
);
940 xdr_encode_word(struct xdr_buf
*buf
, unsigned int base
, u32 obj
)
942 __be32 raw
= cpu_to_be32(obj
);
944 return write_bytes_to_xdr_buf(buf
, base
, &raw
, sizeof(obj
));
946 EXPORT_SYMBOL_GPL(xdr_encode_word
);
948 /* If the netobj starting offset bytes from the start of xdr_buf is contained
949 * entirely in the head or the tail, set object to point to it; otherwise
950 * try to find space for it at the end of the tail, copy it there, and
951 * set obj to point to it. */
952 int xdr_buf_read_netobj(struct xdr_buf
*buf
, struct xdr_netobj
*obj
, unsigned int offset
)
954 struct xdr_buf subbuf
;
956 if (xdr_decode_word(buf
, offset
, &obj
->len
))
958 if (xdr_buf_subsegment(buf
, &subbuf
, offset
+ 4, obj
->len
))
961 /* Is the obj contained entirely in the head? */
962 obj
->data
= subbuf
.head
[0].iov_base
;
963 if (subbuf
.head
[0].iov_len
== obj
->len
)
965 /* ..or is the obj contained entirely in the tail? */
966 obj
->data
= subbuf
.tail
[0].iov_base
;
967 if (subbuf
.tail
[0].iov_len
== obj
->len
)
970 /* use end of tail as storage for obj:
971 * (We don't copy to the beginning because then we'd have
972 * to worry about doing a potentially overlapping copy.
973 * This assumes the object is at most half the length of the
975 if (obj
->len
> buf
->buflen
- buf
->len
)
977 if (buf
->tail
[0].iov_len
!= 0)
978 obj
->data
= buf
->tail
[0].iov_base
+ buf
->tail
[0].iov_len
;
980 obj
->data
= buf
->head
[0].iov_base
+ buf
->head
[0].iov_len
;
981 __read_bytes_from_xdr_buf(&subbuf
, obj
->data
, obj
->len
);
984 EXPORT_SYMBOL_GPL(xdr_buf_read_netobj
);
986 /* Returns 0 on success, or else a negative error code. */
988 xdr_xcode_array2(struct xdr_buf
*buf
, unsigned int base
,
989 struct xdr_array2_desc
*desc
, int encode
)
991 char *elem
= NULL
, *c
;
992 unsigned int copied
= 0, todo
, avail_here
;
993 struct page
**ppages
= NULL
;
997 if (xdr_encode_word(buf
, base
, desc
->array_len
) != 0)
1000 if (xdr_decode_word(buf
, base
, &desc
->array_len
) != 0 ||
1001 desc
->array_len
> desc
->array_maxlen
||
1002 (unsigned long) base
+ 4 + desc
->array_len
*
1003 desc
->elem_size
> buf
->len
)
1011 todo
= desc
->array_len
* desc
->elem_size
;
1014 if (todo
&& base
< buf
->head
->iov_len
) {
1015 c
= buf
->head
->iov_base
+ base
;
1016 avail_here
= min_t(unsigned int, todo
,
1017 buf
->head
->iov_len
- base
);
1020 while (avail_here
>= desc
->elem_size
) {
1021 err
= desc
->xcode(desc
, c
);
1024 c
+= desc
->elem_size
;
1025 avail_here
-= desc
->elem_size
;
1029 elem
= kmalloc(desc
->elem_size
, GFP_KERNEL
);
1035 err
= desc
->xcode(desc
, elem
);
1038 memcpy(c
, elem
, avail_here
);
1040 memcpy(elem
, c
, avail_here
);
1041 copied
= avail_here
;
1043 base
= buf
->head
->iov_len
; /* align to start of pages */
1046 /* process pages array */
1047 base
-= buf
->head
->iov_len
;
1048 if (todo
&& base
< buf
->page_len
) {
1049 unsigned int avail_page
;
1051 avail_here
= min(todo
, buf
->page_len
- base
);
1054 base
+= buf
->page_base
;
1055 ppages
= buf
->pages
+ (base
>> PAGE_CACHE_SHIFT
);
1056 base
&= ~PAGE_CACHE_MASK
;
1057 avail_page
= min_t(unsigned int, PAGE_CACHE_SIZE
- base
,
1059 c
= kmap(*ppages
) + base
;
1061 while (avail_here
) {
1062 avail_here
-= avail_page
;
1063 if (copied
|| avail_page
< desc
->elem_size
) {
1064 unsigned int l
= min(avail_page
,
1065 desc
->elem_size
- copied
);
1067 elem
= kmalloc(desc
->elem_size
,
1075 err
= desc
->xcode(desc
, elem
);
1079 memcpy(c
, elem
+ copied
, l
);
1081 if (copied
== desc
->elem_size
)
1084 memcpy(elem
+ copied
, c
, l
);
1086 if (copied
== desc
->elem_size
) {
1087 err
= desc
->xcode(desc
, elem
);
1096 while (avail_page
>= desc
->elem_size
) {
1097 err
= desc
->xcode(desc
, c
);
1100 c
+= desc
->elem_size
;
1101 avail_page
-= desc
->elem_size
;
1104 unsigned int l
= min(avail_page
,
1105 desc
->elem_size
- copied
);
1107 elem
= kmalloc(desc
->elem_size
,
1115 err
= desc
->xcode(desc
, elem
);
1119 memcpy(c
, elem
+ copied
, l
);
1121 if (copied
== desc
->elem_size
)
1124 memcpy(elem
+ copied
, c
, l
);
1126 if (copied
== desc
->elem_size
) {
1127 err
= desc
->xcode(desc
, elem
);
1140 avail_page
= min(avail_here
,
1141 (unsigned int) PAGE_CACHE_SIZE
);
1143 base
= buf
->page_len
; /* align to start of tail */
1147 base
-= buf
->page_len
;
1149 c
= buf
->tail
->iov_base
+ base
;
1151 unsigned int l
= desc
->elem_size
- copied
;
1154 memcpy(c
, elem
+ copied
, l
);
1156 memcpy(elem
+ copied
, c
, l
);
1157 err
= desc
->xcode(desc
, elem
);
1165 err
= desc
->xcode(desc
, c
);
1168 c
+= desc
->elem_size
;
1169 todo
-= desc
->elem_size
;
1182 xdr_decode_array2(struct xdr_buf
*buf
, unsigned int base
,
1183 struct xdr_array2_desc
*desc
)
1185 if (base
>= buf
->len
)
1188 return xdr_xcode_array2(buf
, base
, desc
, 0);
1190 EXPORT_SYMBOL_GPL(xdr_decode_array2
);
1193 xdr_encode_array2(struct xdr_buf
*buf
, unsigned int base
,
1194 struct xdr_array2_desc
*desc
)
1196 if ((unsigned long) base
+ 4 + desc
->array_len
* desc
->elem_size
>
1197 buf
->head
->iov_len
+ buf
->page_len
+ buf
->tail
->iov_len
)
1200 return xdr_xcode_array2(buf
, base
, desc
, 1);
1202 EXPORT_SYMBOL_GPL(xdr_encode_array2
);
1205 xdr_process_buf(struct xdr_buf
*buf
, unsigned int offset
, unsigned int len
,
1206 int (*actor
)(struct scatterlist
*, void *), void *data
)
1209 unsigned int page_len
, thislen
, page_offset
;
1210 struct scatterlist sg
[1];
1212 sg_init_table(sg
, 1);
1214 if (offset
>= buf
->head
[0].iov_len
) {
1215 offset
-= buf
->head
[0].iov_len
;
1217 thislen
= buf
->head
[0].iov_len
- offset
;
1220 sg_set_buf(sg
, buf
->head
[0].iov_base
+ offset
, thislen
);
1221 ret
= actor(sg
, data
);
1230 if (offset
>= buf
->page_len
) {
1231 offset
-= buf
->page_len
;
1233 page_len
= buf
->page_len
- offset
;
1237 page_offset
= (offset
+ buf
->page_base
) & (PAGE_CACHE_SIZE
- 1);
1238 i
= (offset
+ buf
->page_base
) >> PAGE_CACHE_SHIFT
;
1239 thislen
= PAGE_CACHE_SIZE
- page_offset
;
1241 if (thislen
> page_len
)
1243 sg_set_page(sg
, buf
->pages
[i
], thislen
, page_offset
);
1244 ret
= actor(sg
, data
);
1247 page_len
-= thislen
;
1250 thislen
= PAGE_CACHE_SIZE
;
1251 } while (page_len
!= 0);
1256 if (offset
< buf
->tail
[0].iov_len
) {
1257 thislen
= buf
->tail
[0].iov_len
- offset
;
1260 sg_set_buf(sg
, buf
->tail
[0].iov_base
+ offset
, thislen
);
1261 ret
= actor(sg
, data
);
1269 EXPORT_SYMBOL_GPL(xdr_process_buf
);