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10#include <linux/module.h>
11#include <linux/slab.h>
12#include <linux/types.h>
13#include <linux/string.h>
14#include <linux/kernel.h>
15#include <linux/pagemap.h>
16#include <linux/errno.h>
17#include <linux/sunrpc/xdr.h>
18#include <linux/sunrpc/msg_prot.h>
19#include <linux/bvec.h>
20#include <trace/events/sunrpc.h>
21
22static void _copy_to_pages(struct page **, size_t, const char *, size_t);
23
24
25
26
27
28__be32 *
29xdr_encode_netobj(__be32 *p, const struct xdr_netobj *obj)
30{
31 unsigned int quadlen = XDR_QUADLEN(obj->len);
32
33 p[quadlen] = 0;
34 *p++ = cpu_to_be32(obj->len);
35 memcpy(p, obj->data, obj->len);
36 return p + XDR_QUADLEN(obj->len);
37}
38EXPORT_SYMBOL_GPL(xdr_encode_netobj);
39
40__be32 *
41xdr_decode_netobj(__be32 *p, struct xdr_netobj *obj)
42{
43 unsigned int len;
44
45 if ((len = be32_to_cpu(*p++)) > XDR_MAX_NETOBJ)
46 return NULL;
47 obj->len = len;
48 obj->data = (u8 *) p;
49 return p + XDR_QUADLEN(len);
50}
51EXPORT_SYMBOL_GPL(xdr_decode_netobj);
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65
66
67__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int nbytes)
68{
69 if (likely(nbytes != 0)) {
70 unsigned int quadlen = XDR_QUADLEN(nbytes);
71 unsigned int padding = (quadlen << 2) - nbytes;
72
73 if (ptr != NULL)
74 memcpy(p, ptr, nbytes);
75 if (padding != 0)
76 memset((char *)p + nbytes, 0, padding);
77 p += quadlen;
78 }
79 return p;
80}
81EXPORT_SYMBOL_GPL(xdr_encode_opaque_fixed);
82
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86
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88
89
90
91__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes)
92{
93 *p++ = cpu_to_be32(nbytes);
94 return xdr_encode_opaque_fixed(p, ptr, nbytes);
95}
96EXPORT_SYMBOL_GPL(xdr_encode_opaque);
97
98__be32 *
99xdr_encode_string(__be32 *p, const char *string)
100{
101 return xdr_encode_array(p, string, strlen(string));
102}
103EXPORT_SYMBOL_GPL(xdr_encode_string);
104
105__be32 *
106xdr_decode_string_inplace(__be32 *p, char **sp,
107 unsigned int *lenp, unsigned int maxlen)
108{
109 u32 len;
110
111 len = be32_to_cpu(*p++);
112 if (len > maxlen)
113 return NULL;
114 *lenp = len;
115 *sp = (char *) p;
116 return p + XDR_QUADLEN(len);
117}
118EXPORT_SYMBOL_GPL(xdr_decode_string_inplace);
119
120
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122
123
124
125
126void xdr_terminate_string(const struct xdr_buf *buf, const u32 len)
127{
128 char *kaddr;
129
130 kaddr = kmap_atomic(buf->pages[0]);
131 kaddr[buf->page_base + len] = '\0';
132 kunmap_atomic(kaddr);
133}
134EXPORT_SYMBOL_GPL(xdr_terminate_string);
135
136size_t xdr_buf_pagecount(const struct xdr_buf *buf)
137{
138 if (!buf->page_len)
139 return 0;
140 return (buf->page_base + buf->page_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
141}
142
143int
144xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp)
145{
146 size_t i, n = xdr_buf_pagecount(buf);
147
148 if (n != 0 && buf->bvec == NULL) {
149 buf->bvec = kmalloc_array(n, sizeof(buf->bvec[0]), gfp);
150 if (!buf->bvec)
151 return -ENOMEM;
152 for (i = 0; i < n; i++) {
153 buf->bvec[i].bv_page = buf->pages[i];
154 buf->bvec[i].bv_len = PAGE_SIZE;
155 buf->bvec[i].bv_offset = 0;
156 }
157 }
158 return 0;
159}
160
161void
162xdr_free_bvec(struct xdr_buf *buf)
163{
164 kfree(buf->bvec);
165 buf->bvec = NULL;
166}
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176
177void
178xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
179 struct page **pages, unsigned int base, unsigned int len)
180{
181 struct kvec *head = xdr->head;
182 struct kvec *tail = xdr->tail;
183 char *buf = (char *)head->iov_base;
184 unsigned int buflen = head->iov_len;
185
186 head->iov_len = offset;
187
188 xdr->pages = pages;
189 xdr->page_base = base;
190 xdr->page_len = len;
191
192 tail->iov_base = buf + offset;
193 tail->iov_len = buflen - offset;
194 xdr->buflen += len;
195}
196EXPORT_SYMBOL_GPL(xdr_inline_pages);
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215
216static void
217_shift_data_left_pages(struct page **pages, size_t pgto_base,
218 size_t pgfrom_base, size_t len)
219{
220 struct page **pgfrom, **pgto;
221 char *vfrom, *vto;
222 size_t copy;
223
224 BUG_ON(pgfrom_base <= pgto_base);
225
226 if (!len)
227 return;
228
229 pgto = pages + (pgto_base >> PAGE_SHIFT);
230 pgfrom = pages + (pgfrom_base >> PAGE_SHIFT);
231
232 pgto_base &= ~PAGE_MASK;
233 pgfrom_base &= ~PAGE_MASK;
234
235 do {
236 if (pgto_base >= PAGE_SIZE) {
237 pgto_base = 0;
238 pgto++;
239 }
240 if (pgfrom_base >= PAGE_SIZE){
241 pgfrom_base = 0;
242 pgfrom++;
243 }
244
245 copy = len;
246 if (copy > (PAGE_SIZE - pgto_base))
247 copy = PAGE_SIZE - pgto_base;
248 if (copy > (PAGE_SIZE - pgfrom_base))
249 copy = PAGE_SIZE - pgfrom_base;
250
251 vto = kmap_atomic(*pgto);
252 if (*pgto != *pgfrom) {
253 vfrom = kmap_atomic(*pgfrom);
254 memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);
255 kunmap_atomic(vfrom);
256 } else
257 memmove(vto + pgto_base, vto + pgfrom_base, copy);
258 flush_dcache_page(*pgto);
259 kunmap_atomic(vto);
260
261 pgto_base += copy;
262 pgfrom_base += copy;
263
264 } while ((len -= copy) != 0);
265}
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280
281static void
282_shift_data_right_pages(struct page **pages, size_t pgto_base,
283 size_t pgfrom_base, size_t len)
284{
285 struct page **pgfrom, **pgto;
286 char *vfrom, *vto;
287 size_t copy;
288
289 BUG_ON(pgto_base <= pgfrom_base);
290
291 if (!len)
292 return;
293
294 pgto_base += len;
295 pgfrom_base += len;
296
297 pgto = pages + (pgto_base >> PAGE_SHIFT);
298 pgfrom = pages + (pgfrom_base >> PAGE_SHIFT);
299
300 pgto_base &= ~PAGE_MASK;
301 pgfrom_base &= ~PAGE_MASK;
302
303 do {
304
305 if (pgto_base == 0) {
306 pgto_base = PAGE_SIZE;
307 pgto--;
308 }
309 if (pgfrom_base == 0) {
310 pgfrom_base = PAGE_SIZE;
311 pgfrom--;
312 }
313
314 copy = len;
315 if (copy > pgto_base)
316 copy = pgto_base;
317 if (copy > pgfrom_base)
318 copy = pgfrom_base;
319 pgto_base -= copy;
320 pgfrom_base -= copy;
321
322 vto = kmap_atomic(*pgto);
323 if (*pgto != *pgfrom) {
324 vfrom = kmap_atomic(*pgfrom);
325 memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);
326 kunmap_atomic(vfrom);
327 } else
328 memmove(vto + pgto_base, vto + pgfrom_base, copy);
329 flush_dcache_page(*pgto);
330 kunmap_atomic(vto);
331
332 } while ((len -= copy) != 0);
333}
334
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343
344
345static void
346_copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len)
347{
348 struct page **pgto;
349 char *vto;
350 size_t copy;
351
352 if (!len)
353 return;
354
355 pgto = pages + (pgbase >> PAGE_SHIFT);
356 pgbase &= ~PAGE_MASK;
357
358 for (;;) {
359 copy = PAGE_SIZE - pgbase;
360 if (copy > len)
361 copy = len;
362
363 vto = kmap_atomic(*pgto);
364 memcpy(vto + pgbase, p, copy);
365 kunmap_atomic(vto);
366
367 len -= copy;
368 if (len == 0)
369 break;
370
371 pgbase += copy;
372 if (pgbase == PAGE_SIZE) {
373 flush_dcache_page(*pgto);
374 pgbase = 0;
375 pgto++;
376 }
377 p += copy;
378 }
379 flush_dcache_page(*pgto);
380}
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390
391
392void
393_copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
394{
395 struct page **pgfrom;
396 char *vfrom;
397 size_t copy;
398
399 if (!len)
400 return;
401
402 pgfrom = pages + (pgbase >> PAGE_SHIFT);
403 pgbase &= ~PAGE_MASK;
404
405 do {
406 copy = PAGE_SIZE - pgbase;
407 if (copy > len)
408 copy = len;
409
410 vfrom = kmap_atomic(*pgfrom);
411 memcpy(p, vfrom + pgbase, copy);
412 kunmap_atomic(vfrom);
413
414 pgbase += copy;
415 if (pgbase == PAGE_SIZE) {
416 pgbase = 0;
417 pgfrom++;
418 }
419 p += copy;
420
421 } while ((len -= copy) != 0);
422}
423EXPORT_SYMBOL_GPL(_copy_from_pages);
424
425static void xdr_buf_iov_zero(const struct kvec *iov, unsigned int base,
426 unsigned int len)
427{
428 if (base >= iov->iov_len)
429 return;
430 if (len > iov->iov_len - base)
431 len = iov->iov_len - base;
432 memset(iov->iov_base + base, 0, len);
433}
434
435
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438
439
440
441static void xdr_buf_pages_zero(const struct xdr_buf *buf, unsigned int pgbase,
442 unsigned int len)
443{
444 struct page **pages = buf->pages;
445 struct page **page;
446 char *vpage;
447 unsigned int zero;
448
449 if (!len)
450 return;
451 if (pgbase >= buf->page_len) {
452 xdr_buf_iov_zero(buf->tail, pgbase - buf->page_len, len);
453 return;
454 }
455 if (pgbase + len > buf->page_len) {
456 xdr_buf_iov_zero(buf->tail, 0, pgbase + len - buf->page_len);
457 len = buf->page_len - pgbase;
458 }
459
460 pgbase += buf->page_base;
461
462 page = pages + (pgbase >> PAGE_SHIFT);
463 pgbase &= ~PAGE_MASK;
464
465 do {
466 zero = PAGE_SIZE - pgbase;
467 if (zero > len)
468 zero = len;
469
470 vpage = kmap_atomic(*page);
471 memset(vpage + pgbase, 0, zero);
472 kunmap_atomic(vpage);
473
474 flush_dcache_page(*page);
475 pgbase = 0;
476 page++;
477
478 } while ((len -= zero) != 0);
479}
480
481static unsigned int xdr_buf_pages_fill_sparse(const struct xdr_buf *buf,
482 unsigned int buflen, gfp_t gfp)
483{
484 unsigned int i, npages, pagelen;
485
486 if (!(buf->flags & XDRBUF_SPARSE_PAGES))
487 return buflen;
488 if (buflen <= buf->head->iov_len)
489 return buflen;
490 pagelen = buflen - buf->head->iov_len;
491 if (pagelen > buf->page_len)
492 pagelen = buf->page_len;
493 npages = (pagelen + buf->page_base + PAGE_SIZE - 1) >> PAGE_SHIFT;
494 for (i = 0; i < npages; i++) {
495 if (!buf->pages[i])
496 continue;
497 buf->pages[i] = alloc_page(gfp);
498 if (likely(buf->pages[i]))
499 continue;
500 buflen -= pagelen;
501 pagelen = i << PAGE_SHIFT;
502 if (pagelen > buf->page_base)
503 buflen += pagelen - buf->page_base;
504 break;
505 }
506 return buflen;
507}
508
509static void xdr_buf_try_expand(struct xdr_buf *buf, unsigned int len)
510{
511 struct kvec *head = buf->head;
512 struct kvec *tail = buf->tail;
513 unsigned int sum = head->iov_len + buf->page_len + tail->iov_len;
514 unsigned int free_space, newlen;
515
516 if (sum > buf->len) {
517 free_space = min_t(unsigned int, sum - buf->len, len);
518 newlen = xdr_buf_pages_fill_sparse(buf, buf->len + free_space,
519 GFP_KERNEL);
520 free_space = newlen - buf->len;
521 buf->len = newlen;
522 len -= free_space;
523 if (!len)
524 return;
525 }
526
527 if (buf->buflen > sum) {
528
529 free_space = min_t(unsigned int, buf->buflen - sum, len);
530 tail->iov_len += free_space;
531 buf->len += free_space;
532 }
533}
534
535static void xdr_buf_tail_copy_right(const struct xdr_buf *buf,
536 unsigned int base, unsigned int len,
537 unsigned int shift)
538{
539 const struct kvec *tail = buf->tail;
540 unsigned int to = base + shift;
541
542 if (to >= tail->iov_len)
543 return;
544 if (len + to > tail->iov_len)
545 len = tail->iov_len - to;
546 memmove(tail->iov_base + to, tail->iov_base + base, len);
547}
548
549static void xdr_buf_pages_copy_right(const struct xdr_buf *buf,
550 unsigned int base, unsigned int len,
551 unsigned int shift)
552{
553 const struct kvec *tail = buf->tail;
554 unsigned int to = base + shift;
555 unsigned int pglen = 0;
556 unsigned int talen = 0, tato = 0;
557
558 if (base >= buf->page_len)
559 return;
560 if (len > buf->page_len - base)
561 len = buf->page_len - base;
562 if (to >= buf->page_len) {
563 tato = to - buf->page_len;
564 if (tail->iov_len >= len + tato)
565 talen = len;
566 else if (tail->iov_len > tato)
567 talen = tail->iov_len - tato;
568 } else if (len + to >= buf->page_len) {
569 pglen = buf->page_len - to;
570 talen = len - pglen;
571 if (talen > tail->iov_len)
572 talen = tail->iov_len;
573 } else
574 pglen = len;
575
576 _copy_from_pages(tail->iov_base + tato, buf->pages,
577 buf->page_base + base + pglen, talen);
578 _shift_data_right_pages(buf->pages, buf->page_base + to,
579 buf->page_base + base, pglen);
580}
581
582static void xdr_buf_head_copy_right(const struct xdr_buf *buf,
583 unsigned int base, unsigned int len,
584 unsigned int shift)
585{
586 const struct kvec *head = buf->head;
587 const struct kvec *tail = buf->tail;
588 unsigned int to = base + shift;
589 unsigned int pglen = 0, pgto = 0;
590 unsigned int talen = 0, tato = 0;
591
592 if (base >= head->iov_len)
593 return;
594 if (len > head->iov_len - base)
595 len = head->iov_len - base;
596 if (to >= buf->page_len + head->iov_len) {
597 tato = to - buf->page_len - head->iov_len;
598 talen = len;
599 } else if (to >= head->iov_len) {
600 pgto = to - head->iov_len;
601 pglen = len;
602 if (pgto + pglen > buf->page_len) {
603 talen = pgto + pglen - buf->page_len;
604 pglen -= talen;
605 }
606 } else {
607 pglen = len - to;
608 if (pglen > buf->page_len) {
609 talen = pglen - buf->page_len;
610 pglen = buf->page_len;
611 }
612 }
613
614 len -= talen;
615 base += len;
616 if (talen + tato > tail->iov_len)
617 talen = tail->iov_len > tato ? tail->iov_len - tato : 0;
618 memcpy(tail->iov_base + tato, head->iov_base + base, talen);
619
620 len -= pglen;
621 base -= pglen;
622 _copy_to_pages(buf->pages, buf->page_base + pgto, head->iov_base + base,
623 pglen);
624
625 base -= len;
626 memmove(head->iov_base + to, head->iov_base + base, len);
627}
628
629static void xdr_buf_tail_shift_right(const struct xdr_buf *buf,
630 unsigned int base, unsigned int len,
631 unsigned int shift)
632{
633 const struct kvec *tail = buf->tail;
634
635 if (base >= tail->iov_len || !shift || !len)
636 return;
637 xdr_buf_tail_copy_right(buf, base, len, shift);
638}
639
640static void xdr_buf_pages_shift_right(const struct xdr_buf *buf,
641 unsigned int base, unsigned int len,
642 unsigned int shift)
643{
644 if (!shift || !len)
645 return;
646 if (base >= buf->page_len) {
647 xdr_buf_tail_shift_right(buf, base - buf->page_len, len, shift);
648 return;
649 }
650 if (base + len > buf->page_len)
651 xdr_buf_tail_shift_right(buf, 0, base + len - buf->page_len,
652 shift);
653 xdr_buf_pages_copy_right(buf, base, len, shift);
654}
655
656static void xdr_buf_head_shift_right(const struct xdr_buf *buf,
657 unsigned int base, unsigned int len,
658 unsigned int shift)
659{
660 const struct kvec *head = buf->head;
661
662 if (!shift)
663 return;
664 if (base >= head->iov_len) {
665 xdr_buf_pages_shift_right(buf, head->iov_len - base, len,
666 shift);
667 return;
668 }
669 if (base + len > head->iov_len)
670 xdr_buf_pages_shift_right(buf, 0, base + len - head->iov_len,
671 shift);
672 xdr_buf_head_copy_right(buf, base, len, shift);
673}
674
675static void xdr_buf_tail_copy_left(const struct xdr_buf *buf, unsigned int base,
676 unsigned int len, unsigned int shift)
677{
678 const struct kvec *tail = buf->tail;
679
680 if (base >= tail->iov_len)
681 return;
682 if (len > tail->iov_len - base)
683 len = tail->iov_len - base;
684
685 if (shift > buf->page_len + base) {
686 const struct kvec *head = buf->head;
687 unsigned int hdto =
688 head->iov_len + buf->page_len + base - shift;
689 unsigned int hdlen = len;
690
691 if (WARN_ONCE(shift > head->iov_len + buf->page_len + base,
692 "SUNRPC: Misaligned data.\n"))
693 return;
694 if (hdto + hdlen > head->iov_len)
695 hdlen = head->iov_len - hdto;
696 memcpy(head->iov_base + hdto, tail->iov_base + base, hdlen);
697 base += hdlen;
698 len -= hdlen;
699 if (!len)
700 return;
701 }
702
703 if (shift > base) {
704 unsigned int pgto = buf->page_len + base - shift;
705 unsigned int pglen = len;
706
707 if (pgto + pglen > buf->page_len)
708 pglen = buf->page_len - pgto;
709 _copy_to_pages(buf->pages, buf->page_base + pgto,
710 tail->iov_base + base, pglen);
711 base += pglen;
712 len -= pglen;
713 if (!len)
714 return;
715 }
716 memmove(tail->iov_base + base - shift, tail->iov_base + base, len);
717}
718
719static void xdr_buf_pages_copy_left(const struct xdr_buf *buf,
720 unsigned int base, unsigned int len,
721 unsigned int shift)
722{
723 unsigned int pgto;
724
725 if (base >= buf->page_len)
726 return;
727 if (len > buf->page_len - base)
728 len = buf->page_len - base;
729
730 if (shift > base) {
731 const struct kvec *head = buf->head;
732 unsigned int hdto = head->iov_len + base - shift;
733 unsigned int hdlen = len;
734
735 if (WARN_ONCE(shift > head->iov_len + base,
736 "SUNRPC: Misaligned data.\n"))
737 return;
738 if (hdto + hdlen > head->iov_len)
739 hdlen = head->iov_len - hdto;
740 _copy_from_pages(head->iov_base + hdto, buf->pages,
741 buf->page_base + base, hdlen);
742 base += hdlen;
743 len -= hdlen;
744 if (!len)
745 return;
746 }
747 pgto = base - shift;
748 _shift_data_left_pages(buf->pages, buf->page_base + pgto,
749 buf->page_base + base, len);
750}
751
752static void xdr_buf_tail_shift_left(const struct xdr_buf *buf,
753 unsigned int base, unsigned int len,
754 unsigned int shift)
755{
756 if (!shift || !len)
757 return;
758 xdr_buf_tail_copy_left(buf, base, len, shift);
759}
760
761static void xdr_buf_pages_shift_left(const struct xdr_buf *buf,
762 unsigned int base, unsigned int len,
763 unsigned int shift)
764{
765 if (!shift || !len)
766 return;
767 if (base >= buf->page_len) {
768 xdr_buf_tail_shift_left(buf, base - buf->page_len, len, shift);
769 return;
770 }
771 xdr_buf_pages_copy_left(buf, base, len, shift);
772 len += base;
773 if (len <= buf->page_len)
774 return;
775 xdr_buf_tail_copy_left(buf, 0, len - buf->page_len, shift);
776}
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786
787static unsigned int xdr_shrink_bufhead(struct xdr_buf *buf, unsigned int len)
788{
789 struct kvec *head = buf->head;
790 unsigned int shift, buflen = max(buf->len, len);
791
792 WARN_ON_ONCE(len > head->iov_len);
793 if (head->iov_len > buflen) {
794 buf->buflen -= head->iov_len - buflen;
795 head->iov_len = buflen;
796 }
797 if (len >= head->iov_len)
798 return 0;
799 shift = head->iov_len - len;
800 xdr_buf_try_expand(buf, shift);
801 xdr_buf_head_shift_right(buf, len, buflen - len, shift);
802 head->iov_len = len;
803 buf->buflen -= shift;
804 buf->len -= shift;
805 return shift;
806}
807
808
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814
815
816static unsigned int xdr_shrink_pagelen(struct xdr_buf *buf, unsigned int len)
817{
818 unsigned int shift, buflen = buf->len - buf->head->iov_len;
819
820 WARN_ON_ONCE(len > buf->page_len);
821 if (buf->head->iov_len >= buf->len || len > buflen)
822 buflen = len;
823 if (buf->page_len > buflen) {
824 buf->buflen -= buf->page_len - buflen;
825 buf->page_len = buflen;
826 }
827 if (len >= buf->page_len)
828 return 0;
829 shift = buf->page_len - len;
830 xdr_buf_try_expand(buf, shift);
831 xdr_buf_pages_shift_right(buf, len, buflen - len, shift);
832 buf->page_len = len;
833 buf->len -= shift;
834 buf->buflen -= shift;
835 return shift;
836}
837
838void
839xdr_shift_buf(struct xdr_buf *buf, size_t len)
840{
841 xdr_shrink_bufhead(buf, buf->head->iov_len - len);
842}
843EXPORT_SYMBOL_GPL(xdr_shift_buf);
844
845
846
847
848
849unsigned int xdr_stream_pos(const struct xdr_stream *xdr)
850{
851 return (unsigned int)(XDR_QUADLEN(xdr->buf->len) - xdr->nwords) << 2;
852}
853EXPORT_SYMBOL_GPL(xdr_stream_pos);
854
855static void xdr_stream_set_pos(struct xdr_stream *xdr, unsigned int pos)
856{
857 unsigned int blen = xdr->buf->len;
858
859 xdr->nwords = blen > pos ? XDR_QUADLEN(blen) - XDR_QUADLEN(pos) : 0;
860}
861
862static void xdr_stream_page_set_pos(struct xdr_stream *xdr, unsigned int pos)
863{
864 xdr_stream_set_pos(xdr, pos + xdr->buf->head[0].iov_len);
865}
866
867
868
869
870
871unsigned int xdr_page_pos(const struct xdr_stream *xdr)
872{
873 unsigned int pos = xdr_stream_pos(xdr);
874
875 WARN_ON(pos < xdr->buf->head[0].iov_len);
876 return pos - xdr->buf->head[0].iov_len;
877}
878EXPORT_SYMBOL_GPL(xdr_page_pos);
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p,
895 struct rpc_rqst *rqst)
896{
897 struct kvec *iov = buf->head;
898 int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len;
899
900 xdr_reset_scratch_buffer(xdr);
901 BUG_ON(scratch_len < 0);
902 xdr->buf = buf;
903 xdr->iov = iov;
904 xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len);
905 xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len);
906 BUG_ON(iov->iov_len > scratch_len);
907
908 if (p != xdr->p && p != NULL) {
909 size_t len;
910
911 BUG_ON(p < xdr->p || p > xdr->end);
912 len = (char *)p - (char *)xdr->p;
913 xdr->p = p;
914 buf->len += len;
915 iov->iov_len += len;
916 }
917 xdr->rqst = rqst;
918}
919EXPORT_SYMBOL_GPL(xdr_init_encode);
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934inline void xdr_commit_encode(struct xdr_stream *xdr)
935{
936 int shift = xdr->scratch.iov_len;
937 void *page;
938
939 if (shift == 0)
940 return;
941 page = page_address(*xdr->page_ptr);
942 memcpy(xdr->scratch.iov_base, page, shift);
943 memmove(page, page + shift, (void *)xdr->p - page);
944 xdr_reset_scratch_buffer(xdr);
945}
946EXPORT_SYMBOL_GPL(xdr_commit_encode);
947
948static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr,
949 size_t nbytes)
950{
951 __be32 *p;
952 int space_left;
953 int frag1bytes, frag2bytes;
954
955 if (nbytes > PAGE_SIZE)
956 goto out_overflow;
957 if (xdr->buf->len + nbytes > xdr->buf->buflen)
958 goto out_overflow;
959 frag1bytes = (xdr->end - xdr->p) << 2;
960 frag2bytes = nbytes - frag1bytes;
961 if (xdr->iov)
962 xdr->iov->iov_len += frag1bytes;
963 else
964 xdr->buf->page_len += frag1bytes;
965 xdr->page_ptr++;
966 xdr->iov = NULL;
967
968
969
970
971
972
973
974 xdr_set_scratch_buffer(xdr, xdr->p, frag1bytes);
975 p = page_address(*xdr->page_ptr);
976
977
978
979
980 xdr->p = (void *)p + frag2bytes;
981 space_left = xdr->buf->buflen - xdr->buf->len;
982 xdr->end = (void *)p + min_t(int, space_left, PAGE_SIZE);
983 xdr->buf->page_len += frag2bytes;
984 xdr->buf->len += nbytes;
985 return p;
986out_overflow:
987 trace_rpc_xdr_overflow(xdr, nbytes);
988 return NULL;
989}
990
991
992
993
994
995
996
997
998
999
1000__be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes)
1001{
1002 __be32 *p = xdr->p;
1003 __be32 *q;
1004
1005 xdr_commit_encode(xdr);
1006
1007 nbytes += 3;
1008 nbytes &= ~3;
1009 q = p + (nbytes >> 2);
1010 if (unlikely(q > xdr->end || q < p))
1011 return xdr_get_next_encode_buffer(xdr, nbytes);
1012 xdr->p = q;
1013 if (xdr->iov)
1014 xdr->iov->iov_len += nbytes;
1015 else
1016 xdr->buf->page_len += nbytes;
1017 xdr->buf->len += nbytes;
1018 return p;
1019}
1020EXPORT_SYMBOL_GPL(xdr_reserve_space);
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec, size_t nbytes)
1035{
1036 int thislen;
1037 int v = 0;
1038 __be32 *p;
1039
1040
1041
1042
1043
1044 if (xdr->iov == xdr->buf->head) {
1045 xdr->iov = NULL;
1046 xdr->end = xdr->p;
1047 }
1048
1049 while (nbytes) {
1050 thislen = xdr->buf->page_len % PAGE_SIZE;
1051 thislen = min_t(size_t, nbytes, PAGE_SIZE - thislen);
1052
1053 p = xdr_reserve_space(xdr, thislen);
1054 if (!p)
1055 return -EIO;
1056
1057 vec[v].iov_base = p;
1058 vec[v].iov_len = thislen;
1059 v++;
1060 nbytes -= thislen;
1061 }
1062
1063 return v;
1064}
1065EXPORT_SYMBOL_GPL(xdr_reserve_space_vec);
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086void xdr_truncate_encode(struct xdr_stream *xdr, size_t len)
1087{
1088 struct xdr_buf *buf = xdr->buf;
1089 struct kvec *head = buf->head;
1090 struct kvec *tail = buf->tail;
1091 int fraglen;
1092 int new;
1093
1094 if (len > buf->len) {
1095 WARN_ON_ONCE(1);
1096 return;
1097 }
1098 xdr_commit_encode(xdr);
1099
1100 fraglen = min_t(int, buf->len - len, tail->iov_len);
1101 tail->iov_len -= fraglen;
1102 buf->len -= fraglen;
1103 if (tail->iov_len) {
1104 xdr->p = tail->iov_base + tail->iov_len;
1105 WARN_ON_ONCE(!xdr->end);
1106 WARN_ON_ONCE(!xdr->iov);
1107 return;
1108 }
1109 WARN_ON_ONCE(fraglen);
1110 fraglen = min_t(int, buf->len - len, buf->page_len);
1111 buf->page_len -= fraglen;
1112 buf->len -= fraglen;
1113
1114 new = buf->page_base + buf->page_len;
1115
1116 xdr->page_ptr = buf->pages + (new >> PAGE_SHIFT);
1117
1118 if (buf->page_len) {
1119 xdr->p = page_address(*xdr->page_ptr);
1120 xdr->end = (void *)xdr->p + PAGE_SIZE;
1121 xdr->p = (void *)xdr->p + (new % PAGE_SIZE);
1122 WARN_ON_ONCE(xdr->iov);
1123 return;
1124 }
1125 if (fraglen)
1126 xdr->end = head->iov_base + head->iov_len;
1127
1128 xdr->page_ptr--;
1129 head->iov_len = len;
1130 buf->len = len;
1131 xdr->p = head->iov_base + head->iov_len;
1132 xdr->iov = buf->head;
1133}
1134EXPORT_SYMBOL(xdr_truncate_encode);
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen)
1149{
1150 struct xdr_buf *buf = xdr->buf;
1151 int left_in_this_buf = (void *)xdr->end - (void *)xdr->p;
1152 int end_offset = buf->len + left_in_this_buf;
1153
1154 if (newbuflen < 0 || newbuflen < buf->len)
1155 return -1;
1156 if (newbuflen > buf->buflen)
1157 return 0;
1158 if (newbuflen < end_offset)
1159 xdr->end = (void *)xdr->end + newbuflen - end_offset;
1160 buf->buflen = newbuflen;
1161 return 0;
1162}
1163EXPORT_SYMBOL(xdr_restrict_buflen);
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base,
1174 unsigned int len)
1175{
1176 struct xdr_buf *buf = xdr->buf;
1177 struct kvec *iov = buf->tail;
1178 buf->pages = pages;
1179 buf->page_base = base;
1180 buf->page_len = len;
1181
1182 iov->iov_base = (char *)xdr->p;
1183 iov->iov_len = 0;
1184 xdr->iov = iov;
1185
1186 if (len & 3) {
1187 unsigned int pad = 4 - (len & 3);
1188
1189 BUG_ON(xdr->p >= xdr->end);
1190 iov->iov_base = (char *)xdr->p + (len & 3);
1191 iov->iov_len += pad;
1192 len += pad;
1193 *xdr->p++ = 0;
1194 }
1195 buf->buflen += len;
1196 buf->len += len;
1197}
1198EXPORT_SYMBOL_GPL(xdr_write_pages);
1199
1200static unsigned int xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov,
1201 unsigned int base, unsigned int len)
1202{
1203 if (len > iov->iov_len)
1204 len = iov->iov_len;
1205 if (unlikely(base > len))
1206 base = len;
1207 xdr->p = (__be32*)(iov->iov_base + base);
1208 xdr->end = (__be32*)(iov->iov_base + len);
1209 xdr->iov = iov;
1210 xdr->page_ptr = NULL;
1211 return len - base;
1212}
1213
1214static unsigned int xdr_set_tail_base(struct xdr_stream *xdr,
1215 unsigned int base, unsigned int len)
1216{
1217 struct xdr_buf *buf = xdr->buf;
1218
1219 xdr_stream_set_pos(xdr, base + buf->page_len + buf->head->iov_len);
1220 return xdr_set_iov(xdr, buf->tail, base, len);
1221}
1222
1223static unsigned int xdr_set_page_base(struct xdr_stream *xdr,
1224 unsigned int base, unsigned int len)
1225{
1226 unsigned int pgnr;
1227 unsigned int maxlen;
1228 unsigned int pgoff;
1229 unsigned int pgend;
1230 void *kaddr;
1231
1232 maxlen = xdr->buf->page_len;
1233 if (base >= maxlen)
1234 return 0;
1235 else
1236 maxlen -= base;
1237 if (len > maxlen)
1238 len = maxlen;
1239
1240 xdr_stream_page_set_pos(xdr, base);
1241 base += xdr->buf->page_base;
1242
1243 pgnr = base >> PAGE_SHIFT;
1244 xdr->page_ptr = &xdr->buf->pages[pgnr];
1245 kaddr = page_address(*xdr->page_ptr);
1246
1247 pgoff = base & ~PAGE_MASK;
1248 xdr->p = (__be32*)(kaddr + pgoff);
1249
1250 pgend = pgoff + len;
1251 if (pgend > PAGE_SIZE)
1252 pgend = PAGE_SIZE;
1253 xdr->end = (__be32*)(kaddr + pgend);
1254 xdr->iov = NULL;
1255 return len;
1256}
1257
1258static void xdr_set_page(struct xdr_stream *xdr, unsigned int base,
1259 unsigned int len)
1260{
1261 if (xdr_set_page_base(xdr, base, len) == 0) {
1262 base -= xdr->buf->page_len;
1263 xdr_set_tail_base(xdr, base, len);
1264 }
1265}
1266
1267static void xdr_set_next_page(struct xdr_stream *xdr)
1268{
1269 unsigned int newbase;
1270
1271 newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT;
1272 newbase -= xdr->buf->page_base;
1273 if (newbase < xdr->buf->page_len)
1274 xdr_set_page_base(xdr, newbase, xdr_stream_remaining(xdr));
1275 else
1276 xdr_set_tail_base(xdr, 0, xdr_stream_remaining(xdr));
1277}
1278
1279static bool xdr_set_next_buffer(struct xdr_stream *xdr)
1280{
1281 if (xdr->page_ptr != NULL)
1282 xdr_set_next_page(xdr);
1283 else if (xdr->iov == xdr->buf->head)
1284 xdr_set_page(xdr, 0, xdr_stream_remaining(xdr));
1285 return xdr->p != xdr->end;
1286}
1287
1288
1289
1290
1291
1292
1293
1294
1295void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p,
1296 struct rpc_rqst *rqst)
1297{
1298 xdr->buf = buf;
1299 xdr_reset_scratch_buffer(xdr);
1300 xdr->nwords = XDR_QUADLEN(buf->len);
1301 if (xdr_set_iov(xdr, buf->head, 0, buf->len) == 0 &&
1302 xdr_set_page_base(xdr, 0, buf->len) == 0)
1303 xdr_set_iov(xdr, buf->tail, 0, buf->len);
1304 if (p != NULL && p > xdr->p && xdr->end >= p) {
1305 xdr->nwords -= p - xdr->p;
1306 xdr->p = p;
1307 }
1308 xdr->rqst = rqst;
1309}
1310EXPORT_SYMBOL_GPL(xdr_init_decode);
1311
1312
1313
1314
1315
1316
1317
1318
1319void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
1320 struct page **pages, unsigned int len)
1321{
1322 memset(buf, 0, sizeof(*buf));
1323 buf->pages = pages;
1324 buf->page_len = len;
1325 buf->buflen = len;
1326 buf->len = len;
1327 xdr_init_decode(xdr, buf, NULL, NULL);
1328}
1329EXPORT_SYMBOL_GPL(xdr_init_decode_pages);
1330
1331static __be32 * __xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
1332{
1333 unsigned int nwords = XDR_QUADLEN(nbytes);
1334 __be32 *p = xdr->p;
1335 __be32 *q = p + nwords;
1336
1337 if (unlikely(nwords > xdr->nwords || q > xdr->end || q < p))
1338 return NULL;
1339 xdr->p = q;
1340 xdr->nwords -= nwords;
1341 return p;
1342}
1343
1344static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes)
1345{
1346 __be32 *p;
1347 char *cpdest = xdr->scratch.iov_base;
1348 size_t cplen = (char *)xdr->end - (char *)xdr->p;
1349
1350 if (nbytes > xdr->scratch.iov_len)
1351 goto out_overflow;
1352 p = __xdr_inline_decode(xdr, cplen);
1353 if (p == NULL)
1354 return NULL;
1355 memcpy(cpdest, p, cplen);
1356 if (!xdr_set_next_buffer(xdr))
1357 goto out_overflow;
1358 cpdest += cplen;
1359 nbytes -= cplen;
1360 p = __xdr_inline_decode(xdr, nbytes);
1361 if (p == NULL)
1362 return NULL;
1363 memcpy(cpdest, p, nbytes);
1364 return xdr->scratch.iov_base;
1365out_overflow:
1366 trace_rpc_xdr_overflow(xdr, nbytes);
1367 return NULL;
1368}
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380__be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
1381{
1382 __be32 *p;
1383
1384 if (unlikely(nbytes == 0))
1385 return xdr->p;
1386 if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))
1387 goto out_overflow;
1388 p = __xdr_inline_decode(xdr, nbytes);
1389 if (p != NULL)
1390 return p;
1391 return xdr_copy_to_scratch(xdr, nbytes);
1392out_overflow:
1393 trace_rpc_xdr_overflow(xdr, nbytes);
1394 return NULL;
1395}
1396EXPORT_SYMBOL_GPL(xdr_inline_decode);
1397
1398static void xdr_realign_pages(struct xdr_stream *xdr)
1399{
1400 struct xdr_buf *buf = xdr->buf;
1401 struct kvec *iov = buf->head;
1402 unsigned int cur = xdr_stream_pos(xdr);
1403 unsigned int copied;
1404
1405
1406 if (iov->iov_len > cur) {
1407 copied = xdr_shrink_bufhead(buf, cur);
1408 trace_rpc_xdr_alignment(xdr, cur, copied);
1409 xdr_set_page(xdr, 0, buf->page_len);
1410 }
1411}
1412
1413static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len)
1414{
1415 struct xdr_buf *buf = xdr->buf;
1416 unsigned int nwords = XDR_QUADLEN(len);
1417 unsigned int copied;
1418
1419 if (xdr->nwords == 0)
1420 return 0;
1421
1422 xdr_realign_pages(xdr);
1423 if (nwords > xdr->nwords) {
1424 nwords = xdr->nwords;
1425 len = nwords << 2;
1426 }
1427 if (buf->page_len <= len)
1428 len = buf->page_len;
1429 else if (nwords < xdr->nwords) {
1430
1431 copied = xdr_shrink_pagelen(buf, len);
1432 trace_rpc_xdr_alignment(xdr, len, copied);
1433 }
1434 return len;
1435}
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len)
1450{
1451 unsigned int nwords = XDR_QUADLEN(len);
1452 unsigned int base, end, pglen;
1453
1454 pglen = xdr_align_pages(xdr, nwords << 2);
1455 if (pglen == 0)
1456 return 0;
1457
1458 base = (nwords << 2) - pglen;
1459 end = xdr_stream_remaining(xdr) - pglen;
1460
1461 xdr_set_tail_base(xdr, base, end);
1462 return len <= pglen ? len : pglen;
1463}
1464EXPORT_SYMBOL_GPL(xdr_read_pages);
1465
1466unsigned int xdr_align_data(struct xdr_stream *xdr, unsigned int offset,
1467 unsigned int length)
1468{
1469 struct xdr_buf *buf = xdr->buf;
1470 unsigned int from, bytes, len;
1471 unsigned int shift;
1472
1473 xdr_realign_pages(xdr);
1474 from = xdr_page_pos(xdr);
1475
1476 if (from >= buf->page_len + buf->tail->iov_len)
1477 return 0;
1478 if (from + buf->head->iov_len >= buf->len)
1479 return 0;
1480
1481 len = buf->len - buf->head->iov_len;
1482
1483
1484 if (WARN_ONCE(from < offset, "SUNRPC: misaligned data src=%u dst=%u\n",
1485 from, offset))
1486 return 0;
1487 if (WARN_ONCE(offset > buf->page_len,
1488 "SUNRPC: buffer overflow. offset=%u, page_len=%u\n",
1489 offset, buf->page_len))
1490 return 0;
1491
1492
1493 shift = from - offset;
1494 xdr_buf_pages_shift_left(buf, from, len, shift);
1495
1496 bytes = xdr_stream_remaining(xdr);
1497 if (length > bytes)
1498 length = bytes;
1499 bytes -= length;
1500
1501 xdr->buf->len -= shift;
1502 xdr_set_page(xdr, offset + length, bytes);
1503 return length;
1504}
1505EXPORT_SYMBOL_GPL(xdr_align_data);
1506
1507unsigned int xdr_expand_hole(struct xdr_stream *xdr, unsigned int offset,
1508 unsigned int length)
1509{
1510 struct xdr_buf *buf = xdr->buf;
1511 unsigned int from, to, shift;
1512
1513 xdr_realign_pages(xdr);
1514 from = xdr_page_pos(xdr);
1515 to = xdr_align_size(offset + length);
1516
1517
1518 if (to > from) {
1519 unsigned int buflen = buf->len - buf->head->iov_len;
1520 shift = to - from;
1521 xdr_buf_try_expand(buf, shift);
1522 xdr_buf_pages_shift_right(buf, from, buflen, shift);
1523 xdr_set_page(xdr, to, xdr_stream_remaining(xdr));
1524 } else if (to != from)
1525 xdr_align_data(xdr, to, 0);
1526 xdr_buf_pages_zero(buf, offset, length);
1527
1528 return length;
1529}
1530EXPORT_SYMBOL_GPL(xdr_expand_hole);
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542void xdr_enter_page(struct xdr_stream *xdr, unsigned int len)
1543{
1544 len = xdr_align_pages(xdr, len);
1545
1546
1547
1548
1549 if (len != 0)
1550 xdr_set_page_base(xdr, 0, len);
1551}
1552EXPORT_SYMBOL_GPL(xdr_enter_page);
1553
1554static const struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0};
1555
1556void xdr_buf_from_iov(const struct kvec *iov, struct xdr_buf *buf)
1557{
1558 buf->head[0] = *iov;
1559 buf->tail[0] = empty_iov;
1560 buf->page_len = 0;
1561 buf->buflen = buf->len = iov->iov_len;
1562}
1563EXPORT_SYMBOL_GPL(xdr_buf_from_iov);
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579int xdr_buf_subsegment(const struct xdr_buf *buf, struct xdr_buf *subbuf,
1580 unsigned int base, unsigned int len)
1581{
1582 subbuf->buflen = subbuf->len = len;
1583 if (base < buf->head[0].iov_len) {
1584 subbuf->head[0].iov_base = buf->head[0].iov_base + base;
1585 subbuf->head[0].iov_len = min_t(unsigned int, len,
1586 buf->head[0].iov_len - base);
1587 len -= subbuf->head[0].iov_len;
1588 base = 0;
1589 } else {
1590 base -= buf->head[0].iov_len;
1591 subbuf->head[0].iov_base = buf->head[0].iov_base;
1592 subbuf->head[0].iov_len = 0;
1593 }
1594
1595 if (base < buf->page_len) {
1596 subbuf->page_len = min(buf->page_len - base, len);
1597 base += buf->page_base;
1598 subbuf->page_base = base & ~PAGE_MASK;
1599 subbuf->pages = &buf->pages[base >> PAGE_SHIFT];
1600 len -= subbuf->page_len;
1601 base = 0;
1602 } else {
1603 base -= buf->page_len;
1604 subbuf->pages = buf->pages;
1605 subbuf->page_base = 0;
1606 subbuf->page_len = 0;
1607 }
1608
1609 if (base < buf->tail[0].iov_len) {
1610 subbuf->tail[0].iov_base = buf->tail[0].iov_base + base;
1611 subbuf->tail[0].iov_len = min_t(unsigned int, len,
1612 buf->tail[0].iov_len - base);
1613 len -= subbuf->tail[0].iov_len;
1614 base = 0;
1615 } else {
1616 base -= buf->tail[0].iov_len;
1617 subbuf->tail[0].iov_base = buf->tail[0].iov_base;
1618 subbuf->tail[0].iov_len = 0;
1619 }
1620
1621 if (base || len)
1622 return -1;
1623 return 0;
1624}
1625EXPORT_SYMBOL_GPL(xdr_buf_subsegment);
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
1643 unsigned int nbytes)
1644{
1645 unsigned int remaining, offset, len;
1646
1647 if (xdr_buf_subsegment(xdr->buf, subbuf, xdr_stream_pos(xdr), nbytes))
1648 return false;
1649
1650 if (subbuf->head[0].iov_len)
1651 if (!__xdr_inline_decode(xdr, subbuf->head[0].iov_len))
1652 return false;
1653
1654 remaining = subbuf->page_len;
1655 offset = subbuf->page_base;
1656 while (remaining) {
1657 len = min_t(unsigned int, remaining, PAGE_SIZE) - offset;
1658
1659 if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))
1660 return false;
1661 if (!__xdr_inline_decode(xdr, len))
1662 return false;
1663
1664 remaining -= len;
1665 offset = 0;
1666 }
1667
1668 return true;
1669}
1670EXPORT_SYMBOL_GPL(xdr_stream_subsegment);
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682void xdr_buf_trim(struct xdr_buf *buf, unsigned int len)
1683{
1684 size_t cur;
1685 unsigned int trim = len;
1686
1687 if (buf->tail[0].iov_len) {
1688 cur = min_t(size_t, buf->tail[0].iov_len, trim);
1689 buf->tail[0].iov_len -= cur;
1690 trim -= cur;
1691 if (!trim)
1692 goto fix_len;
1693 }
1694
1695 if (buf->page_len) {
1696 cur = min_t(unsigned int, buf->page_len, trim);
1697 buf->page_len -= cur;
1698 trim -= cur;
1699 if (!trim)
1700 goto fix_len;
1701 }
1702
1703 if (buf->head[0].iov_len) {
1704 cur = min_t(size_t, buf->head[0].iov_len, trim);
1705 buf->head[0].iov_len -= cur;
1706 trim -= cur;
1707 }
1708fix_len:
1709 buf->len -= (len - trim);
1710}
1711EXPORT_SYMBOL_GPL(xdr_buf_trim);
1712
1713static void __read_bytes_from_xdr_buf(const struct xdr_buf *subbuf,
1714 void *obj, unsigned int len)
1715{
1716 unsigned int this_len;
1717
1718 this_len = min_t(unsigned int, len, subbuf->head[0].iov_len);
1719 memcpy(obj, subbuf->head[0].iov_base, this_len);
1720 len -= this_len;
1721 obj += this_len;
1722 this_len = min_t(unsigned int, len, subbuf->page_len);
1723 _copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len);
1724 len -= this_len;
1725 obj += this_len;
1726 this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len);
1727 memcpy(obj, subbuf->tail[0].iov_base, this_len);
1728}
1729
1730
1731int read_bytes_from_xdr_buf(const struct xdr_buf *buf, unsigned int base,
1732 void *obj, unsigned int len)
1733{
1734 struct xdr_buf subbuf;
1735 int status;
1736
1737 status = xdr_buf_subsegment(buf, &subbuf, base, len);
1738 if (status != 0)
1739 return status;
1740 __read_bytes_from_xdr_buf(&subbuf, obj, len);
1741 return 0;
1742}
1743EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf);
1744
1745static void __write_bytes_to_xdr_buf(const struct xdr_buf *subbuf,
1746 void *obj, unsigned int len)
1747{
1748 unsigned int this_len;
1749
1750 this_len = min_t(unsigned int, len, subbuf->head[0].iov_len);
1751 memcpy(subbuf->head[0].iov_base, obj, this_len);
1752 len -= this_len;
1753 obj += this_len;
1754 this_len = min_t(unsigned int, len, subbuf->page_len);
1755 _copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len);
1756 len -= this_len;
1757 obj += this_len;
1758 this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len);
1759 memcpy(subbuf->tail[0].iov_base, obj, this_len);
1760}
1761
1762
1763int write_bytes_to_xdr_buf(const struct xdr_buf *buf, unsigned int base,
1764 void *obj, unsigned int len)
1765{
1766 struct xdr_buf subbuf;
1767 int status;
1768
1769 status = xdr_buf_subsegment(buf, &subbuf, base, len);
1770 if (status != 0)
1771 return status;
1772 __write_bytes_to_xdr_buf(&subbuf, obj, len);
1773 return 0;
1774}
1775EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf);
1776
1777int xdr_decode_word(const struct xdr_buf *buf, unsigned int base, u32 *obj)
1778{
1779 __be32 raw;
1780 int status;
1781
1782 status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
1783 if (status)
1784 return status;
1785 *obj = be32_to_cpu(raw);
1786 return 0;
1787}
1788EXPORT_SYMBOL_GPL(xdr_decode_word);
1789
1790int xdr_encode_word(const struct xdr_buf *buf, unsigned int base, u32 obj)
1791{
1792 __be32 raw = cpu_to_be32(obj);
1793
1794 return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj));
1795}
1796EXPORT_SYMBOL_GPL(xdr_encode_word);
1797
1798
1799static int xdr_xcode_array2(const struct xdr_buf *buf, unsigned int base,
1800 struct xdr_array2_desc *desc, int encode)
1801{
1802 char *elem = NULL, *c;
1803 unsigned int copied = 0, todo, avail_here;
1804 struct page **ppages = NULL;
1805 int err;
1806
1807 if (encode) {
1808 if (xdr_encode_word(buf, base, desc->array_len) != 0)
1809 return -EINVAL;
1810 } else {
1811 if (xdr_decode_word(buf, base, &desc->array_len) != 0 ||
1812 desc->array_len > desc->array_maxlen ||
1813 (unsigned long) base + 4 + desc->array_len *
1814 desc->elem_size > buf->len)
1815 return -EINVAL;
1816 }
1817 base += 4;
1818
1819 if (!desc->xcode)
1820 return 0;
1821
1822 todo = desc->array_len * desc->elem_size;
1823
1824
1825 if (todo && base < buf->head->iov_len) {
1826 c = buf->head->iov_base + base;
1827 avail_here = min_t(unsigned int, todo,
1828 buf->head->iov_len - base);
1829 todo -= avail_here;
1830
1831 while (avail_here >= desc->elem_size) {
1832 err = desc->xcode(desc, c);
1833 if (err)
1834 goto out;
1835 c += desc->elem_size;
1836 avail_here -= desc->elem_size;
1837 }
1838 if (avail_here) {
1839 if (!elem) {
1840 elem = kmalloc(desc->elem_size, GFP_KERNEL);
1841 err = -ENOMEM;
1842 if (!elem)
1843 goto out;
1844 }
1845 if (encode) {
1846 err = desc->xcode(desc, elem);
1847 if (err)
1848 goto out;
1849 memcpy(c, elem, avail_here);
1850 } else
1851 memcpy(elem, c, avail_here);
1852 copied = avail_here;
1853 }
1854 base = buf->head->iov_len;
1855 }
1856
1857
1858 base -= buf->head->iov_len;
1859 if (todo && base < buf->page_len) {
1860 unsigned int avail_page;
1861
1862 avail_here = min(todo, buf->page_len - base);
1863 todo -= avail_here;
1864
1865 base += buf->page_base;
1866 ppages = buf->pages + (base >> PAGE_SHIFT);
1867 base &= ~PAGE_MASK;
1868 avail_page = min_t(unsigned int, PAGE_SIZE - base,
1869 avail_here);
1870 c = kmap(*ppages) + base;
1871
1872 while (avail_here) {
1873 avail_here -= avail_page;
1874 if (copied || avail_page < desc->elem_size) {
1875 unsigned int l = min(avail_page,
1876 desc->elem_size - copied);
1877 if (!elem) {
1878 elem = kmalloc(desc->elem_size,
1879 GFP_KERNEL);
1880 err = -ENOMEM;
1881 if (!elem)
1882 goto out;
1883 }
1884 if (encode) {
1885 if (!copied) {
1886 err = desc->xcode(desc, elem);
1887 if (err)
1888 goto out;
1889 }
1890 memcpy(c, elem + copied, l);
1891 copied += l;
1892 if (copied == desc->elem_size)
1893 copied = 0;
1894 } else {
1895 memcpy(elem + copied, c, l);
1896 copied += l;
1897 if (copied == desc->elem_size) {
1898 err = desc->xcode(desc, elem);
1899 if (err)
1900 goto out;
1901 copied = 0;
1902 }
1903 }
1904 avail_page -= l;
1905 c += l;
1906 }
1907 while (avail_page >= desc->elem_size) {
1908 err = desc->xcode(desc, c);
1909 if (err)
1910 goto out;
1911 c += desc->elem_size;
1912 avail_page -= desc->elem_size;
1913 }
1914 if (avail_page) {
1915 unsigned int l = min(avail_page,
1916 desc->elem_size - copied);
1917 if (!elem) {
1918 elem = kmalloc(desc->elem_size,
1919 GFP_KERNEL);
1920 err = -ENOMEM;
1921 if (!elem)
1922 goto out;
1923 }
1924 if (encode) {
1925 if (!copied) {
1926 err = desc->xcode(desc, elem);
1927 if (err)
1928 goto out;
1929 }
1930 memcpy(c, elem + copied, l);
1931 copied += l;
1932 if (copied == desc->elem_size)
1933 copied = 0;
1934 } else {
1935 memcpy(elem + copied, c, l);
1936 copied += l;
1937 if (copied == desc->elem_size) {
1938 err = desc->xcode(desc, elem);
1939 if (err)
1940 goto out;
1941 copied = 0;
1942 }
1943 }
1944 }
1945 if (avail_here) {
1946 kunmap(*ppages);
1947 ppages++;
1948 c = kmap(*ppages);
1949 }
1950
1951 avail_page = min(avail_here,
1952 (unsigned int) PAGE_SIZE);
1953 }
1954 base = buf->page_len;
1955 }
1956
1957
1958 base -= buf->page_len;
1959 if (todo) {
1960 c = buf->tail->iov_base + base;
1961 if (copied) {
1962 unsigned int l = desc->elem_size - copied;
1963
1964 if (encode)
1965 memcpy(c, elem + copied, l);
1966 else {
1967 memcpy(elem + copied, c, l);
1968 err = desc->xcode(desc, elem);
1969 if (err)
1970 goto out;
1971 }
1972 todo -= l;
1973 c += l;
1974 }
1975 while (todo) {
1976 err = desc->xcode(desc, c);
1977 if (err)
1978 goto out;
1979 c += desc->elem_size;
1980 todo -= desc->elem_size;
1981 }
1982 }
1983 err = 0;
1984
1985out:
1986 kfree(elem);
1987 if (ppages)
1988 kunmap(*ppages);
1989 return err;
1990}
1991
1992int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base,
1993 struct xdr_array2_desc *desc)
1994{
1995 if (base >= buf->len)
1996 return -EINVAL;
1997
1998 return xdr_xcode_array2(buf, base, desc, 0);
1999}
2000EXPORT_SYMBOL_GPL(xdr_decode_array2);
2001
2002int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base,
2003 struct xdr_array2_desc *desc)
2004{
2005 if ((unsigned long) base + 4 + desc->array_len * desc->elem_size >
2006 buf->head->iov_len + buf->page_len + buf->tail->iov_len)
2007 return -EINVAL;
2008
2009 return xdr_xcode_array2(buf, base, desc, 1);
2010}
2011EXPORT_SYMBOL_GPL(xdr_encode_array2);
2012
2013int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset,
2014 unsigned int len,
2015 int (*actor)(struct scatterlist *, void *), void *data)
2016{
2017 int i, ret = 0;
2018 unsigned int page_len, thislen, page_offset;
2019 struct scatterlist sg[1];
2020
2021 sg_init_table(sg, 1);
2022
2023 if (offset >= buf->head[0].iov_len) {
2024 offset -= buf->head[0].iov_len;
2025 } else {
2026 thislen = buf->head[0].iov_len - offset;
2027 if (thislen > len)
2028 thislen = len;
2029 sg_set_buf(sg, buf->head[0].iov_base + offset, thislen);
2030 ret = actor(sg, data);
2031 if (ret)
2032 goto out;
2033 offset = 0;
2034 len -= thislen;
2035 }
2036 if (len == 0)
2037 goto out;
2038
2039 if (offset >= buf->page_len) {
2040 offset -= buf->page_len;
2041 } else {
2042 page_len = buf->page_len - offset;
2043 if (page_len > len)
2044 page_len = len;
2045 len -= page_len;
2046 page_offset = (offset + buf->page_base) & (PAGE_SIZE - 1);
2047 i = (offset + buf->page_base) >> PAGE_SHIFT;
2048 thislen = PAGE_SIZE - page_offset;
2049 do {
2050 if (thislen > page_len)
2051 thislen = page_len;
2052 sg_set_page(sg, buf->pages[i], thislen, page_offset);
2053 ret = actor(sg, data);
2054 if (ret)
2055 goto out;
2056 page_len -= thislen;
2057 i++;
2058 page_offset = 0;
2059 thislen = PAGE_SIZE;
2060 } while (page_len != 0);
2061 offset = 0;
2062 }
2063 if (len == 0)
2064 goto out;
2065 if (offset < buf->tail[0].iov_len) {
2066 thislen = buf->tail[0].iov_len - offset;
2067 if (thislen > len)
2068 thislen = len;
2069 sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen);
2070 ret = actor(sg, data);
2071 len -= thislen;
2072 }
2073 if (len != 0)
2074 ret = -EINVAL;
2075out:
2076 return ret;
2077}
2078EXPORT_SYMBOL_GPL(xdr_process_buf);
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, size_t size)
2092{
2093 ssize_t ret;
2094 void *p;
2095
2096 ret = xdr_stream_decode_opaque_inline(xdr, &p, size);
2097 if (ret <= 0)
2098 return ret;
2099 memcpy(ptr, p, ret);
2100 return ret;
2101}
2102EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque);
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
2118 size_t maxlen, gfp_t gfp_flags)
2119{
2120 ssize_t ret;
2121 void *p;
2122
2123 ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen);
2124 if (ret > 0) {
2125 *ptr = kmemdup(p, ret, gfp_flags);
2126 if (*ptr != NULL)
2127 return ret;
2128 ret = -ENOMEM;
2129 }
2130 *ptr = NULL;
2131 return ret;
2132}
2133EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque_dup);
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, size_t size)
2147{
2148 ssize_t ret;
2149 void *p;
2150
2151 ret = xdr_stream_decode_opaque_inline(xdr, &p, size);
2152 if (ret > 0) {
2153 memcpy(str, p, ret);
2154 str[ret] = '\0';
2155 return strlen(str);
2156 }
2157 *str = '\0';
2158 return ret;
2159}
2160EXPORT_SYMBOL_GPL(xdr_stream_decode_string);
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
2176 size_t maxlen, gfp_t gfp_flags)
2177{
2178 void *p;
2179 ssize_t ret;
2180
2181 ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen);
2182 if (ret > 0) {
2183 char *s = kmemdup_nul(p, ret, gfp_flags);
2184 if (s != NULL) {
2185 *str = s;
2186 return strlen(s);
2187 }
2188 ret = -ENOMEM;
2189 }
2190 *str = NULL;
2191 return ret;
2192}
2193EXPORT_SYMBOL_GPL(xdr_stream_decode_string_dup);
2194