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], KM_USER0
);
126 kaddr
[buf
->page_base
+ len
] = '\0';
127 kunmap_atomic(kaddr
, KM_USER0
);
129 EXPORT_SYMBOL(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
, KM_USER0
);
236 vfrom
= kmap_atomic(*pgfrom
, KM_USER1
);
237 memmove(vto
+ pgto_base
, vfrom
+ pgfrom_base
, copy
);
238 flush_dcache_page(*pgto
);
239 kunmap_atomic(vfrom
, KM_USER1
);
240 kunmap_atomic(vto
, KM_USER0
);
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
, KM_USER0
);
271 memcpy(vto
+ pgbase
, p
, copy
);
272 kunmap_atomic(vto
, KM_USER0
);
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
, KM_USER0
);
315 memcpy(p
, vfrom
+ pgbase
, copy
);
316 kunmap_atomic(vfrom
, KM_USER0
);
319 if (pgbase
== PAGE_CACHE_SIZE
) {
325 } while ((len
-= copy
) != 0);
331 * @len: bytes to remove from buf->head[0]
333 * Shrinks XDR buffer's header kvec buf->head[0] by
334 * 'len' bytes. The extra data is not lost, but is instead
335 * moved into the inlined pages and/or the tail.
338 xdr_shrink_bufhead(struct xdr_buf
*buf
, size_t len
)
340 struct kvec
*head
, *tail
;
342 unsigned int pglen
= buf
->page_len
;
346 BUG_ON (len
> head
->iov_len
);
348 /* Shift the tail first */
349 if (tail
->iov_len
!= 0) {
350 if (tail
->iov_len
> len
) {
351 copy
= tail
->iov_len
- len
;
352 memmove((char *)tail
->iov_base
+ len
,
353 tail
->iov_base
, copy
);
355 /* Copy from the inlined pages into the tail */
360 if (offs
>= tail
->iov_len
)
362 else if (copy
> tail
->iov_len
- offs
)
363 copy
= tail
->iov_len
- offs
;
365 _copy_from_pages((char *)tail
->iov_base
+ offs
,
367 buf
->page_base
+ pglen
+ offs
- len
,
369 /* Do we also need to copy data from the head into the tail ? */
371 offs
= copy
= len
- pglen
;
372 if (copy
> tail
->iov_len
)
373 copy
= tail
->iov_len
;
374 memcpy(tail
->iov_base
,
375 (char *)head
->iov_base
+
376 head
->iov_len
- offs
,
380 /* Now handle pages */
383 _shift_data_right_pages(buf
->pages
,
384 buf
->page_base
+ len
,
390 _copy_to_pages(buf
->pages
, buf
->page_base
,
391 (char *)head
->iov_base
+ head
->iov_len
- len
,
394 head
->iov_len
-= len
;
396 /* Have we truncated the message? */
397 if (buf
->len
> buf
->buflen
)
398 buf
->len
= buf
->buflen
;
404 * @len: bytes to remove from buf->pages
406 * Shrinks XDR buffer's page array buf->pages by
407 * 'len' bytes. The extra data is not lost, but is instead
408 * moved into the tail.
411 xdr_shrink_pagelen(struct xdr_buf
*buf
, size_t len
)
415 unsigned int pglen
= buf
->page_len
;
416 unsigned int tailbuf_len
;
419 BUG_ON (len
> pglen
);
421 tailbuf_len
= buf
->buflen
- buf
->head
->iov_len
- buf
->page_len
;
423 /* Shift the tail first */
424 if (tailbuf_len
!= 0) {
425 unsigned int free_space
= tailbuf_len
- tail
->iov_len
;
427 if (len
< free_space
)
429 tail
->iov_len
+= free_space
;
432 if (tail
->iov_len
> len
) {
433 char *p
= (char *)tail
->iov_base
+ len
;
434 memmove(p
, tail
->iov_base
, tail
->iov_len
- len
);
436 copy
= tail
->iov_len
;
437 /* Copy from the inlined pages into the tail */
438 _copy_from_pages((char *)tail
->iov_base
,
439 buf
->pages
, buf
->page_base
+ pglen
- len
,
442 buf
->page_len
-= len
;
444 /* Have we truncated the message? */
445 if (buf
->len
> buf
->buflen
)
446 buf
->len
= buf
->buflen
;
450 xdr_shift_buf(struct xdr_buf
*buf
, size_t len
)
452 xdr_shrink_bufhead(buf
, len
);
454 EXPORT_SYMBOL_GPL(xdr_shift_buf
);
457 * xdr_init_encode - Initialize a struct xdr_stream for sending data.
458 * @xdr: pointer to xdr_stream struct
459 * @buf: pointer to XDR buffer in which to encode data
460 * @p: current pointer inside XDR buffer
462 * Note: at the moment the RPC client only passes the length of our
463 * scratch buffer in the xdr_buf's header kvec. Previously this
464 * meant we needed to call xdr_adjust_iovec() after encoding the
465 * data. With the new scheme, the xdr_stream manages the details
466 * of the buffer length, and takes care of adjusting the kvec
469 void xdr_init_encode(struct xdr_stream
*xdr
, struct xdr_buf
*buf
, __be32
*p
)
471 struct kvec
*iov
= buf
->head
;
472 int scratch_len
= buf
->buflen
- buf
->page_len
- buf
->tail
[0].iov_len
;
474 BUG_ON(scratch_len
< 0);
477 xdr
->p
= (__be32
*)((char *)iov
->iov_base
+ iov
->iov_len
);
478 xdr
->end
= (__be32
*)((char *)iov
->iov_base
+ scratch_len
);
479 BUG_ON(iov
->iov_len
> scratch_len
);
481 if (p
!= xdr
->p
&& p
!= NULL
) {
484 BUG_ON(p
< xdr
->p
|| p
> xdr
->end
);
485 len
= (char *)p
- (char *)xdr
->p
;
491 EXPORT_SYMBOL_GPL(xdr_init_encode
);
494 * xdr_reserve_space - Reserve buffer space for sending
495 * @xdr: pointer to xdr_stream
496 * @nbytes: number of bytes to reserve
498 * Checks that we have enough buffer space to encode 'nbytes' more
499 * bytes of data. If so, update the total xdr_buf length, and
500 * adjust the length of the current kvec.
502 __be32
* xdr_reserve_space(struct xdr_stream
*xdr
, size_t nbytes
)
507 /* align nbytes on the next 32-bit boundary */
510 q
= p
+ (nbytes
>> 2);
511 if (unlikely(q
> xdr
->end
|| q
< p
))
514 xdr
->iov
->iov_len
+= nbytes
;
515 xdr
->buf
->len
+= nbytes
;
518 EXPORT_SYMBOL_GPL(xdr_reserve_space
);
521 * xdr_write_pages - Insert a list of pages into an XDR buffer for sending
522 * @xdr: pointer to xdr_stream
523 * @pages: list of pages
524 * @base: offset of first byte
525 * @len: length of data in bytes
528 void xdr_write_pages(struct xdr_stream
*xdr
, struct page
**pages
, unsigned int base
,
531 struct xdr_buf
*buf
= xdr
->buf
;
532 struct kvec
*iov
= buf
->tail
;
534 buf
->page_base
= base
;
537 iov
->iov_base
= (char *)xdr
->p
;
542 unsigned int pad
= 4 - (len
& 3);
544 BUG_ON(xdr
->p
>= xdr
->end
);
545 iov
->iov_base
= (char *)xdr
->p
+ (len
& 3);
553 EXPORT_SYMBOL_GPL(xdr_write_pages
);
556 * xdr_init_decode - Initialize an xdr_stream for decoding data.
557 * @xdr: pointer to xdr_stream struct
558 * @buf: pointer to XDR buffer from which to decode data
559 * @p: current pointer inside XDR buffer
561 void xdr_init_decode(struct xdr_stream
*xdr
, struct xdr_buf
*buf
, __be32
*p
)
563 struct kvec
*iov
= buf
->head
;
564 unsigned int len
= iov
->iov_len
;
571 xdr
->end
= (__be32
*)((char *)iov
->iov_base
+ len
);
573 EXPORT_SYMBOL_GPL(xdr_init_decode
);
576 * xdr_inline_peek - Allow read-ahead in the XDR data stream
577 * @xdr: pointer to xdr_stream struct
578 * @nbytes: number of bytes of data to decode
580 * Check if the input buffer is long enough to enable us to decode
581 * 'nbytes' more bytes of data starting at the current position.
582 * If so return the current pointer without updating the current
585 __be32
* xdr_inline_peek(struct xdr_stream
*xdr
, size_t nbytes
)
588 __be32
*q
= p
+ XDR_QUADLEN(nbytes
);
590 if (unlikely(q
> xdr
->end
|| q
< p
))
594 EXPORT_SYMBOL_GPL(xdr_inline_peek
);
597 * xdr_inline_decode - Retrieve non-page XDR data to decode
598 * @xdr: pointer to xdr_stream struct
599 * @nbytes: number of bytes of data to decode
601 * Check if the input buffer is long enough to enable us to decode
602 * 'nbytes' more bytes of data starting at the current position.
603 * If so return the current pointer, then update the current
606 __be32
* xdr_inline_decode(struct xdr_stream
*xdr
, size_t nbytes
)
609 __be32
*q
= p
+ XDR_QUADLEN(nbytes
);
611 if (unlikely(q
> xdr
->end
|| q
< p
))
616 EXPORT_SYMBOL_GPL(xdr_inline_decode
);
619 * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position
620 * @xdr: pointer to xdr_stream struct
621 * @len: number of bytes of page data
623 * Moves data beyond the current pointer position from the XDR head[] buffer
624 * into the page list. Any data that lies beyond current position + "len"
625 * bytes is moved into the XDR tail[].
627 void xdr_read_pages(struct xdr_stream
*xdr
, unsigned int len
)
629 struct xdr_buf
*buf
= xdr
->buf
;
635 /* Realign pages to current pointer position */
637 shift
= iov
->iov_len
+ (char *)iov
->iov_base
- (char *)xdr
->p
;
639 xdr_shrink_bufhead(buf
, shift
);
641 /* Truncate page data and move it into the tail */
642 if (buf
->page_len
> len
)
643 xdr_shrink_pagelen(buf
, buf
->page_len
- len
);
644 padding
= (XDR_QUADLEN(len
) << 2) - len
;
645 xdr
->iov
= iov
= buf
->tail
;
646 /* Compute remaining message length. */
648 shift
= buf
->buflen
- buf
->len
;
654 * Position current pointer at beginning of tail, and
655 * set remaining message length.
657 xdr
->p
= (__be32
*)((char *)iov
->iov_base
+ padding
);
658 xdr
->end
= (__be32
*)((char *)iov
->iov_base
+ end
);
660 EXPORT_SYMBOL_GPL(xdr_read_pages
);
663 * xdr_enter_page - decode data from the XDR page
664 * @xdr: pointer to xdr_stream struct
665 * @len: number of bytes of page data
667 * Moves data beyond the current pointer position from the XDR head[] buffer
668 * into the page list. Any data that lies beyond current position + "len"
669 * bytes is moved into the XDR tail[]. The current pointer is then
670 * repositioned at the beginning of the first XDR page.
672 void xdr_enter_page(struct xdr_stream
*xdr
, unsigned int len
)
674 char * kaddr
= page_address(xdr
->buf
->pages
[0]);
675 xdr_read_pages(xdr
, len
);
677 * Position current pointer at beginning of tail, and
678 * set remaining message length.
680 if (len
> PAGE_CACHE_SIZE
- xdr
->buf
->page_base
)
681 len
= PAGE_CACHE_SIZE
- xdr
->buf
->page_base
;
682 xdr
->p
= (__be32
*)(kaddr
+ xdr
->buf
->page_base
);
683 xdr
->end
= (__be32
*)((char *)xdr
->p
+ len
);
685 EXPORT_SYMBOL_GPL(xdr_enter_page
);
687 static struct kvec empty_iov
= {.iov_base
= NULL
, .iov_len
= 0};
690 xdr_buf_from_iov(struct kvec
*iov
, struct xdr_buf
*buf
)
693 buf
->tail
[0] = empty_iov
;
695 buf
->buflen
= buf
->len
= iov
->iov_len
;
697 EXPORT_SYMBOL_GPL(xdr_buf_from_iov
);
699 /* Sets subbuf to the portion of buf of length len beginning base bytes
700 * from the start of buf. Returns -1 if base of length are out of bounds. */
702 xdr_buf_subsegment(struct xdr_buf
*buf
, struct xdr_buf
*subbuf
,
703 unsigned int base
, unsigned int len
)
705 subbuf
->buflen
= subbuf
->len
= len
;
706 if (base
< buf
->head
[0].iov_len
) {
707 subbuf
->head
[0].iov_base
= buf
->head
[0].iov_base
+ base
;
708 subbuf
->head
[0].iov_len
= min_t(unsigned int, len
,
709 buf
->head
[0].iov_len
- base
);
710 len
-= subbuf
->head
[0].iov_len
;
713 subbuf
->head
[0].iov_base
= NULL
;
714 subbuf
->head
[0].iov_len
= 0;
715 base
-= buf
->head
[0].iov_len
;
718 if (base
< buf
->page_len
) {
719 subbuf
->page_len
= min(buf
->page_len
- base
, len
);
720 base
+= buf
->page_base
;
721 subbuf
->page_base
= base
& ~PAGE_CACHE_MASK
;
722 subbuf
->pages
= &buf
->pages
[base
>> PAGE_CACHE_SHIFT
];
723 len
-= subbuf
->page_len
;
726 base
-= buf
->page_len
;
727 subbuf
->page_len
= 0;
730 if (base
< buf
->tail
[0].iov_len
) {
731 subbuf
->tail
[0].iov_base
= buf
->tail
[0].iov_base
+ base
;
732 subbuf
->tail
[0].iov_len
= min_t(unsigned int, len
,
733 buf
->tail
[0].iov_len
- base
);
734 len
-= subbuf
->tail
[0].iov_len
;
737 subbuf
->tail
[0].iov_base
= NULL
;
738 subbuf
->tail
[0].iov_len
= 0;
739 base
-= buf
->tail
[0].iov_len
;
746 EXPORT_SYMBOL_GPL(xdr_buf_subsegment
);
748 static void __read_bytes_from_xdr_buf(struct xdr_buf
*subbuf
, void *obj
, unsigned int len
)
750 unsigned int this_len
;
752 this_len
= min_t(unsigned int, len
, subbuf
->head
[0].iov_len
);
753 memcpy(obj
, subbuf
->head
[0].iov_base
, this_len
);
756 this_len
= min_t(unsigned int, len
, subbuf
->page_len
);
758 _copy_from_pages(obj
, subbuf
->pages
, subbuf
->page_base
, this_len
);
761 this_len
= min_t(unsigned int, len
, subbuf
->tail
[0].iov_len
);
762 memcpy(obj
, subbuf
->tail
[0].iov_base
, this_len
);
765 /* obj is assumed to point to allocated memory of size at least len: */
766 int read_bytes_from_xdr_buf(struct xdr_buf
*buf
, unsigned int base
, void *obj
, unsigned int len
)
768 struct xdr_buf subbuf
;
771 status
= xdr_buf_subsegment(buf
, &subbuf
, base
, len
);
774 __read_bytes_from_xdr_buf(&subbuf
, obj
, len
);
777 EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf
);
779 static void __write_bytes_to_xdr_buf(struct xdr_buf
*subbuf
, void *obj
, unsigned int len
)
781 unsigned int this_len
;
783 this_len
= min_t(unsigned int, len
, subbuf
->head
[0].iov_len
);
784 memcpy(subbuf
->head
[0].iov_base
, obj
, this_len
);
787 this_len
= min_t(unsigned int, len
, subbuf
->page_len
);
789 _copy_to_pages(subbuf
->pages
, subbuf
->page_base
, obj
, this_len
);
792 this_len
= min_t(unsigned int, len
, subbuf
->tail
[0].iov_len
);
793 memcpy(subbuf
->tail
[0].iov_base
, obj
, this_len
);
796 /* obj is assumed to point to allocated memory of size at least len: */
797 int write_bytes_to_xdr_buf(struct xdr_buf
*buf
, unsigned int base
, void *obj
, unsigned int len
)
799 struct xdr_buf subbuf
;
802 status
= xdr_buf_subsegment(buf
, &subbuf
, base
, len
);
805 __write_bytes_to_xdr_buf(&subbuf
, obj
, len
);
808 EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf
);
811 xdr_decode_word(struct xdr_buf
*buf
, unsigned int base
, u32
*obj
)
816 status
= read_bytes_from_xdr_buf(buf
, base
, &raw
, sizeof(*obj
));
819 *obj
= be32_to_cpu(raw
);
822 EXPORT_SYMBOL_GPL(xdr_decode_word
);
825 xdr_encode_word(struct xdr_buf
*buf
, unsigned int base
, u32 obj
)
827 __be32 raw
= cpu_to_be32(obj
);
829 return write_bytes_to_xdr_buf(buf
, base
, &raw
, sizeof(obj
));
831 EXPORT_SYMBOL_GPL(xdr_encode_word
);
833 /* If the netobj starting offset bytes from the start of xdr_buf is contained
834 * entirely in the head or the tail, set object to point to it; otherwise
835 * try to find space for it at the end of the tail, copy it there, and
836 * set obj to point to it. */
837 int xdr_buf_read_netobj(struct xdr_buf
*buf
, struct xdr_netobj
*obj
, unsigned int offset
)
839 struct xdr_buf subbuf
;
841 if (xdr_decode_word(buf
, offset
, &obj
->len
))
843 if (xdr_buf_subsegment(buf
, &subbuf
, offset
+ 4, obj
->len
))
846 /* Is the obj contained entirely in the head? */
847 obj
->data
= subbuf
.head
[0].iov_base
;
848 if (subbuf
.head
[0].iov_len
== obj
->len
)
850 /* ..or is the obj contained entirely in the tail? */
851 obj
->data
= subbuf
.tail
[0].iov_base
;
852 if (subbuf
.tail
[0].iov_len
== obj
->len
)
855 /* use end of tail as storage for obj:
856 * (We don't copy to the beginning because then we'd have
857 * to worry about doing a potentially overlapping copy.
858 * This assumes the object is at most half the length of the
860 if (obj
->len
> buf
->buflen
- buf
->len
)
862 if (buf
->tail
[0].iov_len
!= 0)
863 obj
->data
= buf
->tail
[0].iov_base
+ buf
->tail
[0].iov_len
;
865 obj
->data
= buf
->head
[0].iov_base
+ buf
->head
[0].iov_len
;
866 __read_bytes_from_xdr_buf(&subbuf
, obj
->data
, obj
->len
);
869 EXPORT_SYMBOL_GPL(xdr_buf_read_netobj
);
871 /* Returns 0 on success, or else a negative error code. */
873 xdr_xcode_array2(struct xdr_buf
*buf
, unsigned int base
,
874 struct xdr_array2_desc
*desc
, int encode
)
876 char *elem
= NULL
, *c
;
877 unsigned int copied
= 0, todo
, avail_here
;
878 struct page
**ppages
= NULL
;
882 if (xdr_encode_word(buf
, base
, desc
->array_len
) != 0)
885 if (xdr_decode_word(buf
, base
, &desc
->array_len
) != 0 ||
886 desc
->array_len
> desc
->array_maxlen
||
887 (unsigned long) base
+ 4 + desc
->array_len
*
888 desc
->elem_size
> buf
->len
)
896 todo
= desc
->array_len
* desc
->elem_size
;
899 if (todo
&& base
< buf
->head
->iov_len
) {
900 c
= buf
->head
->iov_base
+ base
;
901 avail_here
= min_t(unsigned int, todo
,
902 buf
->head
->iov_len
- base
);
905 while (avail_here
>= desc
->elem_size
) {
906 err
= desc
->xcode(desc
, c
);
909 c
+= desc
->elem_size
;
910 avail_here
-= desc
->elem_size
;
914 elem
= kmalloc(desc
->elem_size
, GFP_KERNEL
);
920 err
= desc
->xcode(desc
, elem
);
923 memcpy(c
, elem
, avail_here
);
925 memcpy(elem
, c
, avail_here
);
928 base
= buf
->head
->iov_len
; /* align to start of pages */
931 /* process pages array */
932 base
-= buf
->head
->iov_len
;
933 if (todo
&& base
< buf
->page_len
) {
934 unsigned int avail_page
;
936 avail_here
= min(todo
, buf
->page_len
- base
);
939 base
+= buf
->page_base
;
940 ppages
= buf
->pages
+ (base
>> PAGE_CACHE_SHIFT
);
941 base
&= ~PAGE_CACHE_MASK
;
942 avail_page
= min_t(unsigned int, PAGE_CACHE_SIZE
- base
,
944 c
= kmap(*ppages
) + base
;
947 avail_here
-= avail_page
;
948 if (copied
|| avail_page
< desc
->elem_size
) {
949 unsigned int l
= min(avail_page
,
950 desc
->elem_size
- copied
);
952 elem
= kmalloc(desc
->elem_size
,
960 err
= desc
->xcode(desc
, elem
);
964 memcpy(c
, elem
+ copied
, l
);
966 if (copied
== desc
->elem_size
)
969 memcpy(elem
+ copied
, c
, l
);
971 if (copied
== desc
->elem_size
) {
972 err
= desc
->xcode(desc
, elem
);
981 while (avail_page
>= desc
->elem_size
) {
982 err
= desc
->xcode(desc
, c
);
985 c
+= desc
->elem_size
;
986 avail_page
-= desc
->elem_size
;
989 unsigned int l
= min(avail_page
,
990 desc
->elem_size
- copied
);
992 elem
= kmalloc(desc
->elem_size
,
1000 err
= desc
->xcode(desc
, elem
);
1004 memcpy(c
, elem
+ copied
, l
);
1006 if (copied
== desc
->elem_size
)
1009 memcpy(elem
+ copied
, c
, l
);
1011 if (copied
== desc
->elem_size
) {
1012 err
= desc
->xcode(desc
, elem
);
1025 avail_page
= min(avail_here
,
1026 (unsigned int) PAGE_CACHE_SIZE
);
1028 base
= buf
->page_len
; /* align to start of tail */
1032 base
-= buf
->page_len
;
1034 c
= buf
->tail
->iov_base
+ base
;
1036 unsigned int l
= desc
->elem_size
- copied
;
1039 memcpy(c
, elem
+ copied
, l
);
1041 memcpy(elem
+ copied
, c
, l
);
1042 err
= desc
->xcode(desc
, elem
);
1050 err
= desc
->xcode(desc
, c
);
1053 c
+= desc
->elem_size
;
1054 todo
-= desc
->elem_size
;
1067 xdr_decode_array2(struct xdr_buf
*buf
, unsigned int base
,
1068 struct xdr_array2_desc
*desc
)
1070 if (base
>= buf
->len
)
1073 return xdr_xcode_array2(buf
, base
, desc
, 0);
1075 EXPORT_SYMBOL_GPL(xdr_decode_array2
);
1078 xdr_encode_array2(struct xdr_buf
*buf
, unsigned int base
,
1079 struct xdr_array2_desc
*desc
)
1081 if ((unsigned long) base
+ 4 + desc
->array_len
* desc
->elem_size
>
1082 buf
->head
->iov_len
+ buf
->page_len
+ buf
->tail
->iov_len
)
1085 return xdr_xcode_array2(buf
, base
, desc
, 1);
1087 EXPORT_SYMBOL_GPL(xdr_encode_array2
);
1090 xdr_process_buf(struct xdr_buf
*buf
, unsigned int offset
, unsigned int len
,
1091 int (*actor
)(struct scatterlist
*, void *), void *data
)
1094 unsigned page_len
, thislen
, page_offset
;
1095 struct scatterlist sg
[1];
1097 sg_init_table(sg
, 1);
1099 if (offset
>= buf
->head
[0].iov_len
) {
1100 offset
-= buf
->head
[0].iov_len
;
1102 thislen
= buf
->head
[0].iov_len
- offset
;
1105 sg_set_buf(sg
, buf
->head
[0].iov_base
+ offset
, thislen
);
1106 ret
= actor(sg
, data
);
1115 if (offset
>= buf
->page_len
) {
1116 offset
-= buf
->page_len
;
1118 page_len
= buf
->page_len
- offset
;
1122 page_offset
= (offset
+ buf
->page_base
) & (PAGE_CACHE_SIZE
- 1);
1123 i
= (offset
+ buf
->page_base
) >> PAGE_CACHE_SHIFT
;
1124 thislen
= PAGE_CACHE_SIZE
- page_offset
;
1126 if (thislen
> page_len
)
1128 sg_set_page(sg
, buf
->pages
[i
], thislen
, page_offset
);
1129 ret
= actor(sg
, data
);
1132 page_len
-= thislen
;
1135 thislen
= PAGE_CACHE_SIZE
;
1136 } while (page_len
!= 0);
1141 if (offset
< buf
->tail
[0].iov_len
) {
1142 thislen
= buf
->tail
[0].iov_len
- offset
;
1145 sg_set_buf(sg
, buf
->tail
[0].iov_base
+ offset
, thislen
);
1146 ret
= actor(sg
, data
);
1154 EXPORT_SYMBOL_GPL(xdr_process_buf
);