1 /* crypto/bio/bss_bio.c -*- Mode: C; c-file-style: "eay" -*- */
2 /* ====================================================================
3 * Copyright (c) 1998-2003 The OpenSSL Project. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
16 *
17 * 3. All advertising materials mentioning features or use of this
18 * software must display the following acknowledgment:
19 * "This product includes software developed by the OpenSSL Project
20 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21 *
22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23 * endorse or promote products derived from this software without
24 * prior written permission. For written permission, please contact
25 * openssl-core@openssl.org.
26 *
27 * 5. Products derived from this software may not be called "OpenSSL"
28 * nor may "OpenSSL" appear in their names without prior written
29 * permission of the OpenSSL Project.
30 *
31 * 6. Redistributions of any form whatsoever must retain the following
32 * acknowledgment:
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35 *
36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47 * OF THE POSSIBILITY OF SUCH DAMAGE.
48 * ====================================================================
49 *
50 * This product includes cryptographic software written by Eric Young
51 * (eay@cryptsoft.com). This product includes software written by Tim
52 * Hudson (tjh@cryptsoft.com).
53 *
54 */
55
56 /* Special method for a BIO where the other endpoint is also a BIO
57 * of this kind, handled by the same thread (i.e. the "peer" is actually
58 * ourselves, wearing a different hat).
59 * Such "BIO pairs" are mainly for using the SSL library with I/O interfaces
60 * for which no specific BIO method is available.
61 * See ssl/ssltest.c for some hints on how this can be used. */
62
63 /* BIO_DEBUG implies BIO_PAIR_DEBUG */
64 #ifdef BIO_DEBUG
65 # ifndef BIO_PAIR_DEBUG
66 # define BIO_PAIR_DEBUG
67 # endif
68 #endif
69
70 /* disable assert() unless BIO_PAIR_DEBUG has been defined */
71 #ifndef BIO_PAIR_DEBUG
72 # ifndef NDEBUG
73 # define NDEBUG
74 # endif
75 #endif
76
77 #include <assert.h>
78 #include <limits.h>
79 #include <stdlib.h>
80 #include <string.h>
81
82 #include <openssl/bio.h>
83 #include <openssl/err.h>
84 #include <openssl/crypto.h>
85
86 #include "e_os.h"
87
88 /* VxWorks defines SSIZE_MAX with an empty value causing compile errors */
89 #if defined(OPENSSL_SYS_VXWORKS)
90 # undef SSIZE_MAX
91 #endif
92 #ifndef SSIZE_MAX
93 # define SSIZE_MAX INT_MAX
94 #endif
95
96 static int bio_new(BIO *bio);
97 static int bio_free(BIO *bio);
98 static int bio_read(BIO *bio, char *buf, int size);
99 static int bio_write(BIO *bio, const char *buf, int num);
100 static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr);
101 static int bio_puts(BIO *bio, const char *str);
102
103 static int bio_make_pair(BIO *bio1, BIO *bio2);
104 static void bio_destroy_pair(BIO *bio);
105
106 static BIO_METHOD methods_biop =
107 {
108 BIO_TYPE_BIO,
109 "BIO pair",
110 bio_write,
111 bio_read,
112 bio_puts,
113 NULL /* no bio_gets */,
114 bio_ctrl,
115 bio_new,
116 bio_free,
117 NULL /* no bio_callback_ctrl */
118 };
119
120 BIO_METHOD *BIO_s_bio(void)
121 {
122 return &methods_biop;
123 }
124
125 struct bio_bio_st
126 {
127 BIO *peer; /* NULL if buf == NULL.
128 * If peer != NULL, then peer->ptr is also a bio_bio_st,
129 * and its "peer" member points back to us.
130 * peer != NULL iff init != 0 in the BIO. */
131
132 /* This is for what we write (i.e. reading uses peer's struct): */
133 int closed; /* valid iff peer != NULL */
134 size_t len; /* valid iff buf != NULL; 0 if peer == NULL */
135 size_t offset; /* valid iff buf != NULL; 0 if len == 0 */
136 size_t size;
137 char *buf; /* "size" elements (if != NULL) */
138
139 size_t request; /* valid iff peer != NULL; 0 if len != 0,
140 * otherwise set by peer to number of bytes
141 * it (unsuccessfully) tried to read,
142 * never more than buffer space (size-len) warrants. */
143 };
144
145 static int bio_new(BIO *bio)
146 {
147 struct bio_bio_st *b;
148
149 b = OPENSSL_malloc(sizeof *b);
150 if (b == NULL)
151 return 0;
152
153 b->peer = NULL;
154 b->size = 17*1024; /* enough for one TLS record (just a default) */
155 b->buf = NULL;
156
157 bio->ptr = b;
158 return 1;
159 }
160
161
162 static int bio_free(BIO *bio)
163 {
164 struct bio_bio_st *b;
165
166 if (bio == NULL)
167 return 0;
168 b = bio->ptr;
169
170 assert(b != NULL);
171
172 if (b->peer)
173 bio_destroy_pair(bio);
174
175 if (b->buf != NULL)
176 {
177 OPENSSL_free(b->buf);
178 }
179
180 OPENSSL_free(b);
181
182 return 1;
183 }
184
185
186
187 static int bio_read(BIO *bio, char *buf, int size_)
188 {
189 size_t size = size_;
190 size_t rest;
191 struct bio_bio_st *b, *peer_b;
192
193 BIO_clear_retry_flags(bio);
194
195 if (!bio->init)
196 return 0;
197
198 b = bio->ptr;
199 assert(b != NULL);
200 assert(b->peer != NULL);
201 peer_b = b->peer->ptr;
202 assert(peer_b != NULL);
203 assert(peer_b->buf != NULL);
204
205 peer_b->request = 0; /* will be set in "retry_read" situation */
206
207 if (buf == NULL || size == 0)
208 return 0;
209
210 if (peer_b->len == 0)
211 {
212 if (peer_b->closed)
213 return 0; /* writer has closed, and no data is left */
214 else
215 {
216 BIO_set_retry_read(bio); /* buffer is empty */
217 if (size <= peer_b->size)
218 peer_b->request = size;
219 else
220 /* don't ask for more than the peer can
221 * deliver in one write */
222 peer_b->request = peer_b->size;
223 return -1;
224 }
225 }
226
227 /* we can read */
228 if (peer_b->len < size)
229 size = peer_b->len;
230
231 /* now read "size" bytes */
232
233 rest = size;
234
235 assert(rest > 0);
236 do /* one or two iterations */
237 {
238 size_t chunk;
239
240 assert(rest <= peer_b->len);
241 if (peer_b->offset + rest <= peer_b->size)
242 chunk = rest;
243 else
244 /* wrap around ring buffer */
245 chunk = peer_b->size - peer_b->offset;
246 assert(peer_b->offset + chunk <= peer_b->size);
247
248 memcpy(buf, peer_b->buf + peer_b->offset, chunk);
249
250 peer_b->len -= chunk;
251 if (peer_b->len)
252 {
253 peer_b->offset += chunk;
254 assert(peer_b->offset <= peer_b->size);
255 if (peer_b->offset == peer_b->size)
256 peer_b->offset = 0;
257 buf += chunk;
258 }
259 else
260 {
261 /* buffer now empty, no need to advance "buf" */
262 assert(chunk == rest);
263 peer_b->offset = 0;
264 }
265 rest -= chunk;
266 }
267 while (rest);
268
269 return size;
270 }
271
272 /* non-copying interface: provide pointer to available data in buffer
273 * bio_nread0: return number of available bytes
274 * bio_nread: also advance index
275 * (example usage: bio_nread0(), read from buffer, bio_nread()
276 * or just bio_nread(), read from buffer)
277 */
278 /* WARNING: The non-copying interface is largely untested as of yet
279 * and may contain bugs. */
280 static ossl_ssize_t bio_nread0(BIO *bio, char **buf)
281 {
282 struct bio_bio_st *b, *peer_b;
283 ossl_ssize_t num;
284
285 BIO_clear_retry_flags(bio);
286
287 if (!bio->init)
288 return 0;
289
290 b = bio->ptr;
291 assert(b != NULL);
292 assert(b->peer != NULL);
293 peer_b = b->peer->ptr;
294 assert(peer_b != NULL);
295 assert(peer_b->buf != NULL);
296
297 peer_b->request = 0;
298
299 if (peer_b->len == 0)
300 {
301 char dummy;
302
303 /* avoid code duplication -- nothing available for reading */
304 return bio_read(bio, &dummy, 1); /* returns 0 or -1 */
305 }
306
307 num = peer_b->len;
308 if (peer_b->size < peer_b->offset + num)
309 /* no ring buffer wrap-around for non-copying interface */
310 num = peer_b->size - peer_b->offset;
311 assert(num > 0);
312
313 if (buf != NULL)
314 *buf = peer_b->buf + peer_b->offset;
315 return num;
316 }
317
318 static ossl_ssize_t bio_nread(BIO *bio, char **buf, size_t num_)
319 {
320 struct bio_bio_st *b, *peer_b;
321 ossl_ssize_t num, available;
322
323 if (num_ > SSIZE_MAX)
324 num = SSIZE_MAX;
325 else
326 num = (ossl_ssize_t)num_;
327
328 available = bio_nread0(bio, buf);
329 if (num > available)
330 num = available;
331 if (num <= 0)
332 return num;
333
334 b = bio->ptr;
335 peer_b = b->peer->ptr;
336
337 peer_b->len -= num;
338 if (peer_b->len)
339 {
340 peer_b->offset += num;
341 assert(peer_b->offset <= peer_b->size);
342 if (peer_b->offset == peer_b->size)
343 peer_b->offset = 0;
344 }
345 else
346 peer_b->offset = 0;
347
348 return num;
349 }
350
351
352 static int bio_write(BIO *bio, const char *buf, int num_)
353 {
354 size_t num = num_;
355 size_t rest;
356 struct bio_bio_st *b;
357
358 BIO_clear_retry_flags(bio);
359
360 if (!bio->init || buf == NULL || num == 0)
361 return 0;
362
363 b = bio->ptr;
364 assert(b != NULL);
365 assert(b->peer != NULL);
366 assert(b->buf != NULL);
367
368 b->request = 0;
369 if (b->closed)
370 {
371 /* we already closed */
372 BIOerr(BIO_F_BIO_WRITE, BIO_R_BROKEN_PIPE);
373 return -1;
374 }
375
376 assert(b->len <= b->size);
377
378 if (b->len == b->size)
379 {
380 BIO_set_retry_write(bio); /* buffer is full */
381 return -1;
382 }
383
384 /* we can write */
385 if (num > b->size - b->len)
386 num = b->size - b->len;
387
388 /* now write "num" bytes */
389
390 rest = num;
391
392 assert(rest > 0);
393 do /* one or two iterations */
394 {
395 size_t write_offset;
396 size_t chunk;
397
398 assert(b->len + rest <= b->size);
399
400 write_offset = b->offset + b->len;
401 if (write_offset >= b->size)
402 write_offset -= b->size;
403 /* b->buf[write_offset] is the first byte we can write to. */
404
405 if (write_offset + rest <= b->size)
406 chunk = rest;
407 else
408 /* wrap around ring buffer */
409 chunk = b->size - write_offset;
410
411 memcpy(b->buf + write_offset, buf, chunk);
412
413 b->len += chunk;
414
415 assert(b->len <= b->size);
416
417 rest -= chunk;
418 buf += chunk;
419 }
420 while (rest);
421
422 return num;
423 }
424
425 /* non-copying interface: provide pointer to region to write to
426 * bio_nwrite0: check how much space is available
427 * bio_nwrite: also increase length
428 * (example usage: bio_nwrite0(), write to buffer, bio_nwrite()
429 * or just bio_nwrite(), write to buffer)
430 */
431 static ossl_ssize_t bio_nwrite0(BIO *bio, char **buf)
432 {
433 struct bio_bio_st *b;
434 size_t num;
435 size_t write_offset;
436
437 BIO_clear_retry_flags(bio);
438
439 if (!bio->init)
440 return 0;
441
442 b = bio->ptr;
443 assert(b != NULL);
444 assert(b->peer != NULL);
445 assert(b->buf != NULL);
446
447 b->request = 0;
448 if (b->closed)
449 {
450 BIOerr(BIO_F_BIO_NWRITE0, BIO_R_BROKEN_PIPE);
451 return -1;
452 }
453
454 assert(b->len <= b->size);
455
456 if (b->len == b->size)
457 {
458 BIO_set_retry_write(bio);
459 return -1;
460 }
461
462 num = b->size - b->len;
463 write_offset = b->offset + b->len;
464 if (write_offset >= b->size)
465 write_offset -= b->size;
466 if (write_offset + num > b->size)
467 /* no ring buffer wrap-around for non-copying interface
468 * (to fulfil the promise by BIO_ctrl_get_write_guarantee,
469 * BIO_nwrite may have to be called twice) */
470 num = b->size - write_offset;
471
472 if (buf != NULL)
473 *buf = b->buf + write_offset;
474 assert(write_offset + num <= b->size);
475
476 return num;
477 }
478
479 static ossl_ssize_t bio_nwrite(BIO *bio, char **buf, size_t num_)
480 {
481 struct bio_bio_st *b;
482 ossl_ssize_t num, space;
483
484 if (num_ > SSIZE_MAX)
485 num = SSIZE_MAX;
486 else
487 num = (ossl_ssize_t)num_;
488
489 space = bio_nwrite0(bio, buf);
490 if (num > space)
491 num = space;
492 if (num <= 0)
493 return num;
494 b = bio->ptr;
495 assert(b != NULL);
496 b->len += num;
497 assert(b->len <= b->size);
498
499 return num;
500 }
501
502
503 static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr)
504 {
505 long ret;
506 struct bio_bio_st *b = bio->ptr;
507
508 assert(b != NULL);
509
510 switch (cmd)
511 {
512 /* specific CTRL codes */
513
514 case BIO_C_SET_WRITE_BUF_SIZE:
515 if (b->peer)
516 {
517 BIOerr(BIO_F_BIO_CTRL, BIO_R_IN_USE);
518 ret = 0;
519 }
520 else if (num == 0)
521 {
522 BIOerr(BIO_F_BIO_CTRL, BIO_R_INVALID_ARGUMENT);
523 ret = 0;
524 }
525 else
526 {
527 size_t new_size = num;
528
529 if (b->size != new_size)
530 {
531 if (b->buf)
532 {
533 OPENSSL_free(b->buf);
534 b->buf = NULL;
535 }
536 b->size = new_size;
537 }
538 ret = 1;
539 }
540 break;
541
542 case BIO_C_GET_WRITE_BUF_SIZE:
543 ret = (long) b->size;
544 break;
545
546 case BIO_C_MAKE_BIO_PAIR:
547 {
548 BIO *other_bio = ptr;
549
550 if (bio_make_pair(bio, other_bio))
551 ret = 1;
552 else
553 ret = 0;
554 }
555 break;
556
557 case BIO_C_DESTROY_BIO_PAIR:
558 /* Affects both BIOs in the pair -- call just once!
559 * Or let BIO_free(bio1); BIO_free(bio2); do the job. */
560 bio_destroy_pair(bio);
561 ret = 1;
562 break;
563
564 case BIO_C_GET_WRITE_GUARANTEE:
565 /* How many bytes can the caller feed to the next write
566 * without having to keep any? */
567 if (b->peer == NULL || b->closed)
568 ret = 0;
569 else
570 ret = (long) b->size - b->len;
571 break;
572
573 case BIO_C_GET_READ_REQUEST:
574 /* If the peer unsuccessfully tried to read, how many bytes
575 * were requested? (As with BIO_CTRL_PENDING, that number
576 * can usually be treated as boolean.) */
577 ret = (long) b->request;
578 break;
579
580 case BIO_C_RESET_READ_REQUEST:
581 /* Reset request. (Can be useful after read attempts
582 * at the other side that are meant to be non-blocking,
583 * e.g. when probing SSL_read to see if any data is
584 * available.) */
585 b->request = 0;
586 ret = 1;
587 break;
588
589 case BIO_C_SHUTDOWN_WR:
590 /* similar to shutdown(..., SHUT_WR) */
591 b->closed = 1;
592 ret = 1;
593 break;
594
595 case BIO_C_NREAD0:
596 /* prepare for non-copying read */
597 ret = (long) bio_nread0(bio, ptr);
598 break;
599
600 case BIO_C_NREAD:
601 /* non-copying read */
602 ret = (long) bio_nread(bio, ptr, (size_t) num);
603 break;
604
605 case BIO_C_NWRITE0:
606 /* prepare for non-copying write */
607 ret = (long) bio_nwrite0(bio, ptr);
608 break;
609
610 case BIO_C_NWRITE:
611 /* non-copying write */
612 ret = (long) bio_nwrite(bio, ptr, (size_t) num);
613 break;
614
615
616 /* standard CTRL codes follow */
617
618 case BIO_CTRL_RESET:
619 if (b->buf != NULL)
620 {
621 b->len = 0;
622 b->offset = 0;
623 }
624 ret = 0;
625 break;
626
627 case BIO_CTRL_GET_CLOSE:
628 ret = bio->shutdown;
629 break;
630
631 case BIO_CTRL_SET_CLOSE:
632 bio->shutdown = (int) num;
633 ret = 1;
634 break;
635
636 case BIO_CTRL_PENDING:
637 if (b->peer != NULL)
638 {
639 struct bio_bio_st *peer_b = b->peer->ptr;
640
641 ret = (long) peer_b->len;
642 }
643 else
644 ret = 0;
645 break;
646
647 case BIO_CTRL_WPENDING:
648 if (b->buf != NULL)
649 ret = (long) b->len;
650 else
651 ret = 0;
652 break;
653
654 case BIO_CTRL_DUP:
655 /* See BIO_dup_chain for circumstances we have to expect. */
656 {
657 BIO *other_bio = ptr;
658 struct bio_bio_st *other_b;
659
660 assert(other_bio != NULL);
661 other_b = other_bio->ptr;
662 assert(other_b != NULL);
663
664 assert(other_b->buf == NULL); /* other_bio is always fresh */
665
666 other_b->size = b->size;
667 }
668
669 ret = 1;
670 break;
671
672 case BIO_CTRL_FLUSH:
673 ret = 1;
674 break;
675
676 case BIO_CTRL_EOF:
677 {
678 BIO *other_bio = ptr;
679
680 if (other_bio)
681 {
682 struct bio_bio_st *other_b = other_bio->ptr;
683
684 assert(other_b != NULL);
685 ret = other_b->len == 0 && other_b->closed;
686 }
687 else
688 ret = 1;
689 }
690 break;
691
692 default:
693 ret = 0;
694 }
695 return ret;
696 }
697
698 static int bio_puts(BIO *bio, const char *str)
699 {
700 return bio_write(bio, str, strlen(str));
701 }
702
703
704 static int bio_make_pair(BIO *bio1, BIO *bio2)
705 {
706 struct bio_bio_st *b1, *b2;
707
708 assert(bio1 != NULL);
709 assert(bio2 != NULL);
710
711 b1 = bio1->ptr;
712 b2 = bio2->ptr;
713
714 if (b1->peer != NULL || b2->peer != NULL)
715 {
716 BIOerr(BIO_F_BIO_MAKE_PAIR, BIO_R_IN_USE);
717 return 0;
718 }
719
720 if (b1->buf == NULL)
721 {
722 b1->buf = OPENSSL_malloc(b1->size);
723 if (b1->buf == NULL)
724 {
725 BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
726 return 0;
727 }
728 b1->len = 0;
729 b1->offset = 0;
730 }
731
732 if (b2->buf == NULL)
733 {
734 b2->buf = OPENSSL_malloc(b2->size);
735 if (b2->buf == NULL)
736 {
737 BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
738 return 0;
739 }
740 b2->len = 0;
741 b2->offset = 0;
742 }
743
744 b1->peer = bio2;
745 b1->closed = 0;
746 b1->request = 0;
747 b2->peer = bio1;
748 b2->closed = 0;
749 b2->request = 0;
750
751 bio1->init = 1;
752 bio2->init = 1;
753
754 return 1;
755 }
756
757 static void bio_destroy_pair(BIO *bio)
758 {
759 struct bio_bio_st *b = bio->ptr;
760
761 if (b != NULL)
762 {
763 BIO *peer_bio = b->peer;
764
765 if (peer_bio != NULL)
766 {
767 struct bio_bio_st *peer_b = peer_bio->ptr;
768
769 assert(peer_b != NULL);
770 assert(peer_b->peer == bio);
771
772 peer_b->peer = NULL;
773 peer_bio->init = 0;
774 assert(peer_b->buf != NULL);
775 peer_b->len = 0;
776 peer_b->offset = 0;
777
778 b->peer = NULL;
779 bio->init = 0;
780 assert(b->buf != NULL);
781 b->len = 0;
782 b->offset = 0;
783 }
784 }
785 }
786
787
788 /* Exported convenience functions */
789 int BIO_new_bio_pair(BIO **bio1_p, size_t writebuf1,
790 BIO **bio2_p, size_t writebuf2)
791 {
792 BIO *bio1 = NULL, *bio2 = NULL;
793 long r;
794 int ret = 0;
795
796 bio1 = BIO_new(BIO_s_bio());
797 if (bio1 == NULL)
798 goto err;
799 bio2 = BIO_new(BIO_s_bio());
800 if (bio2 == NULL)
801 goto err;
802
803 if (writebuf1)
804 {
805 r = BIO_set_write_buf_size(bio1, writebuf1);
806 if (!r)
807 goto err;
808 }
809 if (writebuf2)
810 {
811 r = BIO_set_write_buf_size(bio2, writebuf2);
812 if (!r)
813 goto err;
814 }
815
816 r = BIO_make_bio_pair(bio1, bio2);
817 if (!r)
818 goto err;
819 ret = 1;
820
821 err:
822 if (ret == 0)
823 {
824 if (bio1)
825 {
826 BIO_free(bio1);
827 bio1 = NULL;
828 }
829 if (bio2)
830 {
831 BIO_free(bio2);
832 bio2 = NULL;
833 }
834 }
835
836 *bio1_p = bio1;
837 *bio2_p = bio2;
838 return ret;
839 }
840
841 size_t BIO_ctrl_get_write_guarantee(BIO *bio)
842 {
843 return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL);
844 }
845
846 size_t BIO_ctrl_get_read_request(BIO *bio)
847 {
848 return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL);
849 }
850
851 int BIO_ctrl_reset_read_request(BIO *bio)
852 {
853 return (BIO_ctrl(bio, BIO_C_RESET_READ_REQUEST, 0, NULL) != 0);
854 }
855
856
857 /* BIO_nread0/nread/nwrite0/nwrite are available only for BIO pairs for now
858 * (conceivably some other BIOs could allow non-copying reads and writes too.)
859 */
860 int BIO_nread0(BIO *bio, char **buf)
861 {
862 long ret;
863
864 if (!bio->init)
865 {
866 BIOerr(BIO_F_BIO_NREAD0, BIO_R_UNINITIALIZED);
867 return -2;
868 }
869
870 ret = BIO_ctrl(bio, BIO_C_NREAD0, 0, buf);
871 if (ret > INT_MAX)
872 return INT_MAX;
873 else
874 return (int) ret;
875 }
876
877 int BIO_nread(BIO *bio, char **buf, int num)
878 {
879 int ret;
880
881 if (!bio->init)
882 {
883 BIOerr(BIO_F_BIO_NREAD, BIO_R_UNINITIALIZED);
884 return -2;
885 }
886
887 ret = (int) BIO_ctrl(bio, BIO_C_NREAD, num, buf);
888 if (ret > 0)
889 bio->num_read += ret;
890 return ret;
891 }
892
893 int BIO_nwrite0(BIO *bio, char **buf)
894 {
895 long ret;
896
897 if (!bio->init)
898 {
899 BIOerr(BIO_F_BIO_NWRITE0, BIO_R_UNINITIALIZED);
900 return -2;
901 }
902
903 ret = BIO_ctrl(bio, BIO_C_NWRITE0, 0, buf);
904 if (ret > INT_MAX)
905 return INT_MAX;
906 else
907 return (int) ret;
908 }
909
910 int BIO_nwrite(BIO *bio, char **buf, int num)
911 {
912 int ret;
913
914 if (!bio->init)
915 {
916 BIOerr(BIO_F_BIO_NWRITE, BIO_R_UNINITIALIZED);
917 return -2;
918 }
919
920 ret = BIO_ctrl(bio, BIO_C_NWRITE, num, buf);
921 if (ret > 0)
922 bio->num_write += ret;
923 return ret;
924 }