xref: /openbsd/lib/libcrypto/bio/bss_bio.c (revision 5af055cd)
1 /* $OpenBSD: bss_bio.c,v 1.22 2015/12/23 20:37:23 mmcc Exp $ */
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 #include <sys/types.h>
82 
83 #include <openssl/bio.h>
84 #include <openssl/err.h>
85 #include <openssl/crypto.h>
86 
87 static int bio_new(BIO *bio);
88 static int bio_free(BIO *bio);
89 static int bio_read(BIO *bio, char *buf, int size);
90 static int bio_write(BIO *bio, const char *buf, int num);
91 static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr);
92 static int bio_puts(BIO *bio, const char *str);
93 
94 static int bio_make_pair(BIO *bio1, BIO *bio2);
95 static void bio_destroy_pair(BIO *bio);
96 
97 static BIO_METHOD methods_biop = {
98 	.type = BIO_TYPE_BIO,
99 	.name = "BIO pair",
100 	.bwrite = bio_write,
101 	.bread = bio_read,
102 	.bputs = bio_puts,
103 	.ctrl = bio_ctrl,
104 	.create = bio_new,
105 	.destroy = bio_free
106 };
107 
108 BIO_METHOD *
109 BIO_s_bio(void)
110 {
111 	return &methods_biop;
112 }
113 
114 struct bio_bio_st {
115 	BIO *peer;	/* NULL if buf == NULL.
116 			 * If peer != NULL, then peer->ptr is also a bio_bio_st,
117 			 * and its "peer" member points back to us.
118 			 * peer != NULL iff init != 0 in the BIO. */
119 
120 	/* This is for what we write (i.e. reading uses peer's struct): */
121 	int closed;	/* valid iff peer != NULL */
122 	size_t len;	/* valid iff buf != NULL; 0 if peer == NULL */
123 	size_t offset;	/* valid iff buf != NULL; 0 if len == 0 */
124 	size_t size;
125 	char *buf;      /* "size" elements (if != NULL) */
126 
127 	size_t request; /* valid iff peer != NULL; 0 if len != 0,
128 			 * otherwise set by peer to number of bytes
129 			 * it (unsuccessfully) tried to read,
130 	                 * never more than buffer space (size-len) warrants. */
131 };
132 
133 static int
134 bio_new(BIO *bio)
135 {
136 	struct bio_bio_st *b;
137 
138 	b = malloc(sizeof *b);
139 	if (b == NULL)
140 		return 0;
141 
142 	b->peer = NULL;
143 	b->size = 17 * 1024; /* enough for one TLS record (just a default) */
144 	b->buf = NULL;
145 
146 	bio->ptr = b;
147 	return 1;
148 }
149 
150 static int
151 bio_free(BIO *bio)
152 {
153 	struct bio_bio_st *b;
154 
155 	if (bio == NULL)
156 		return 0;
157 	b = bio->ptr;
158 
159 	assert(b != NULL);
160 
161 	if (b->peer)
162 		bio_destroy_pair(bio);
163 
164 	free(b->buf);
165 	free(b);
166 	return 1;
167 }
168 
169 
170 
171 static int
172 bio_read(BIO *bio, char *buf, int size_)
173 {
174 	size_t size = size_;
175 	size_t rest;
176 	struct bio_bio_st *b, *peer_b;
177 
178 	BIO_clear_retry_flags(bio);
179 
180 	if (!bio->init)
181 		return 0;
182 
183 	b = bio->ptr;
184 	assert(b != NULL);
185 	assert(b->peer != NULL);
186 	peer_b = b->peer->ptr;
187 	assert(peer_b != NULL);
188 	assert(peer_b->buf != NULL);
189 
190 	peer_b->request = 0; /* will be set in "retry_read" situation */
191 
192 	if (buf == NULL || size == 0)
193 		return 0;
194 
195 	if (peer_b->len == 0) {
196 		if (peer_b->closed)
197 			return 0; /* writer has closed, and no data is left */
198 		else {
199 			BIO_set_retry_read(bio); /* buffer is empty */
200 			if (size <= peer_b->size)
201 				peer_b->request = size;
202 			else
203 				/* don't ask for more than the peer can
204 				 * deliver in one write */
205 				peer_b->request = peer_b->size;
206 			return -1;
207 		}
208 	}
209 
210 	/* we can read */
211 	if (peer_b->len < size)
212 		size = peer_b->len;
213 
214 	/* now read "size" bytes */
215 
216 	rest = size;
217 
218 	assert(rest > 0);
219 	do /* one or two iterations */
220 	{
221 		size_t chunk;
222 
223 		assert(rest <= peer_b->len);
224 		if (peer_b->offset + rest <= peer_b->size)
225 			chunk = rest;
226 		else
227 			/* wrap around ring buffer */
228 			chunk = peer_b->size - peer_b->offset;
229 		assert(peer_b->offset + chunk <= peer_b->size);
230 
231 		memcpy(buf, peer_b->buf + peer_b->offset, chunk);
232 
233 		peer_b->len -= chunk;
234 		if (peer_b->len) {
235 			peer_b->offset += chunk;
236 			assert(peer_b->offset <= peer_b->size);
237 			if (peer_b->offset == peer_b->size)
238 				peer_b->offset = 0;
239 			buf += chunk;
240 		} else {
241 			/* buffer now empty, no need to advance "buf" */
242 			assert(chunk == rest);
243 			peer_b->offset = 0;
244 		}
245 		rest -= chunk;
246 	} while (rest);
247 
248 	return size;
249 }
250 
251 /* non-copying interface: provide pointer to available data in buffer
252  *    bio_nread0:  return number of available bytes
253  *    bio_nread:   also advance index
254  * (example usage:  bio_nread0(), read from buffer, bio_nread()
255  *  or just         bio_nread(), read from buffer)
256  */
257 /* WARNING: The non-copying interface is largely untested as of yet
258  * and may contain bugs. */
259 static ssize_t
260 bio_nread0(BIO *bio, char **buf)
261 {
262 	struct bio_bio_st *b, *peer_b;
263 	ssize_t num;
264 
265 	BIO_clear_retry_flags(bio);
266 
267 	if (!bio->init)
268 		return 0;
269 
270 	b = bio->ptr;
271 	assert(b != NULL);
272 	assert(b->peer != NULL);
273 	peer_b = b->peer->ptr;
274 	assert(peer_b != NULL);
275 	assert(peer_b->buf != NULL);
276 
277 	peer_b->request = 0;
278 
279 	if (peer_b->len == 0) {
280 		char dummy;
281 
282 		/* avoid code duplication -- nothing available for reading */
283 		return bio_read(bio, &dummy, 1); /* returns 0 or -1 */
284 	}
285 
286 	num = peer_b->len;
287 	if (peer_b->size < peer_b->offset + num)
288 		/* no ring buffer wrap-around for non-copying interface */
289 		num = peer_b->size - peer_b->offset;
290 	assert(num > 0);
291 
292 	if (buf != NULL)
293 		*buf = peer_b->buf + peer_b->offset;
294 	return num;
295 }
296 
297 static ssize_t
298 bio_nread(BIO *bio, char **buf, size_t num_)
299 {
300 	struct bio_bio_st *b, *peer_b;
301 	ssize_t num, available;
302 
303 	if (num_ > SSIZE_MAX)
304 		num = SSIZE_MAX;
305 	else
306 		num = (ssize_t)num_;
307 
308 	available = bio_nread0(bio, buf);
309 	if (num > available)
310 		num = available;
311 	if (num <= 0)
312 		return num;
313 
314 	b = bio->ptr;
315 	peer_b = b->peer->ptr;
316 
317 	peer_b->len -= num;
318 	if (peer_b->len) {
319 		peer_b->offset += num;
320 		assert(peer_b->offset <= peer_b->size);
321 		if (peer_b->offset == peer_b->size)
322 			peer_b->offset = 0;
323 	} else
324 		peer_b->offset = 0;
325 
326 	return num;
327 }
328 
329 
330 static int
331 bio_write(BIO *bio, const char *buf, int num_)
332 {
333 	size_t num = num_;
334 	size_t rest;
335 	struct bio_bio_st *b;
336 
337 	BIO_clear_retry_flags(bio);
338 
339 	if (!bio->init || buf == NULL || num == 0)
340 		return 0;
341 
342 	b = bio->ptr;
343 
344 	assert(b != NULL);
345 	assert(b->peer != NULL);
346 	assert(b->buf != NULL);
347 
348 	b->request = 0;
349 	if (b->closed) {
350 		/* we already closed */
351 		BIOerr(BIO_F_BIO_WRITE, BIO_R_BROKEN_PIPE);
352 		return -1;
353 	}
354 
355 	assert(b->len <= b->size);
356 
357 	if (b->len == b->size) {
358 		BIO_set_retry_write(bio); /* buffer is full */
359 		return -1;
360 	}
361 
362 	/* we can write */
363 	if (num > b->size - b->len)
364 		num = b->size - b->len;
365 
366 	/* now write "num" bytes */
367 
368 	rest = num;
369 
370 	assert(rest > 0);
371 	do /* one or two iterations */
372 	{
373 		size_t write_offset;
374 		size_t chunk;
375 
376 		assert(b->len + rest <= b->size);
377 
378 		write_offset = b->offset + b->len;
379 		if (write_offset >= b->size)
380 			write_offset -= b->size;
381 		/* b->buf[write_offset] is the first byte we can write to. */
382 
383 		if (write_offset + rest <= b->size)
384 			chunk = rest;
385 		else
386 			/* wrap around ring buffer */
387 			chunk = b->size - write_offset;
388 
389 		memcpy(b->buf + write_offset, buf, chunk);
390 
391 		b->len += chunk;
392 
393 		assert(b->len <= b->size);
394 
395 		rest -= chunk;
396 		buf += chunk;
397 	} while (rest);
398 
399 	return num;
400 }
401 
402 /* non-copying interface: provide pointer to region to write to
403  *   bio_nwrite0:  check how much space is available
404  *   bio_nwrite:   also increase length
405  * (example usage:  bio_nwrite0(), write to buffer, bio_nwrite()
406  *  or just         bio_nwrite(), write to buffer)
407  */
408 static ssize_t
409 bio_nwrite0(BIO *bio, char **buf)
410 {
411 	struct bio_bio_st *b;
412 	size_t num;
413 	size_t write_offset;
414 
415 	BIO_clear_retry_flags(bio);
416 
417 	if (!bio->init)
418 		return 0;
419 
420 	b = bio->ptr;
421 
422 	assert(b != NULL);
423 	assert(b->peer != NULL);
424 	assert(b->buf != NULL);
425 
426 	b->request = 0;
427 	if (b->closed) {
428 		BIOerr(BIO_F_BIO_NWRITE0, BIO_R_BROKEN_PIPE);
429 		return -1;
430 	}
431 
432 	assert(b->len <= b->size);
433 
434 	if (b->len == b->size) {
435 		BIO_set_retry_write(bio);
436 		return -1;
437 	}
438 
439 	num = b->size - b->len;
440 	write_offset = b->offset + b->len;
441 	if (write_offset >= b->size)
442 		write_offset -= b->size;
443 	if (write_offset + num > b->size)
444 		/* no ring buffer wrap-around for non-copying interface
445 		 * (to fulfil the promise by BIO_ctrl_get_write_guarantee,
446 		 * BIO_nwrite may have to be called twice) */
447 		num = b->size - write_offset;
448 
449 	if (buf != NULL)
450 		*buf = b->buf + write_offset;
451 	assert(write_offset + num <= b->size);
452 
453 	return num;
454 }
455 
456 static ssize_t
457 bio_nwrite(BIO *bio, char **buf, size_t num_)
458 {
459 	struct bio_bio_st *b;
460 	ssize_t num, space;
461 
462 	if (num_ > SSIZE_MAX)
463 		num = SSIZE_MAX;
464 	else
465 		num = (ssize_t)num_;
466 
467 	space = bio_nwrite0(bio, buf);
468 	if (num > space)
469 		num = space;
470 	if (num <= 0)
471 		return num;
472 	b = bio->ptr;
473 	assert(b != NULL);
474 	b->len += num;
475 	assert(b->len <= b->size);
476 
477 	return num;
478 }
479 
480 
481 static long
482 bio_ctrl(BIO *bio, int cmd, long num, void *ptr)
483 {
484 	long ret;
485 	struct bio_bio_st *b = bio->ptr;
486 
487 	assert(b != NULL);
488 
489 	switch (cmd) {
490 		/* specific CTRL codes */
491 
492 	case BIO_C_SET_WRITE_BUF_SIZE:
493 		if (b->peer) {
494 			BIOerr(BIO_F_BIO_CTRL, BIO_R_IN_USE);
495 			ret = 0;
496 		} else if (num == 0) {
497 			BIOerr(BIO_F_BIO_CTRL, BIO_R_INVALID_ARGUMENT);
498 			ret = 0;
499 		} else {
500 			size_t new_size = num;
501 
502 			if (b->size != new_size) {
503 				free(b->buf);
504 				b->buf = NULL;
505 				b->size = new_size;
506 			}
507 			ret = 1;
508 		}
509 		break;
510 
511 	case BIO_C_GET_WRITE_BUF_SIZE:
512 		ret = (long) b->size;
513 		break;
514 
515 	case BIO_C_MAKE_BIO_PAIR:
516 		{
517 			BIO *other_bio = ptr;
518 
519 			if (bio_make_pair(bio, other_bio))
520 				ret = 1;
521 			else
522 				ret = 0;
523 		}
524 		break;
525 
526 	case BIO_C_DESTROY_BIO_PAIR:
527 		/* Affects both BIOs in the pair -- call just once!
528 		 * Or let BIO_free(bio1); BIO_free(bio2); do the job. */
529 		bio_destroy_pair(bio);
530 		ret = 1;
531 		break;
532 
533 	case BIO_C_GET_WRITE_GUARANTEE:
534 		/* How many bytes can the caller feed to the next write
535 		 * without having to keep any? */
536 		if (b->peer == NULL || b->closed)
537 			ret = 0;
538 		else
539 			ret = (long) b->size - b->len;
540 		break;
541 
542 	case BIO_C_GET_READ_REQUEST:
543 		/* If the peer unsuccessfully tried to read, how many bytes
544 		 * were requested?  (As with BIO_CTRL_PENDING, that number
545 		 * can usually be treated as boolean.) */
546 		ret = (long) b->request;
547 		break;
548 
549 	case BIO_C_RESET_READ_REQUEST:
550 		/* Reset request.  (Can be useful after read attempts
551 		 * at the other side that are meant to be non-blocking,
552 		 * e.g. when probing SSL_read to see if any data is
553 		 * available.) */
554 		b->request = 0;
555 		ret = 1;
556 		break;
557 
558 	case BIO_C_SHUTDOWN_WR:
559 		/* similar to shutdown(..., SHUT_WR) */
560 		b->closed = 1;
561 		ret = 1;
562 		break;
563 
564 	case BIO_C_NREAD0:
565 		/* prepare for non-copying read */
566 		ret = (long) bio_nread0(bio, ptr);
567 		break;
568 
569 	case BIO_C_NREAD:
570 		/* non-copying read */
571 		ret = (long) bio_nread(bio, ptr, (size_t) num);
572 		break;
573 
574 	case BIO_C_NWRITE0:
575 		/* prepare for non-copying write */
576 		ret = (long) bio_nwrite0(bio, ptr);
577 		break;
578 
579 	case BIO_C_NWRITE:
580 		/* non-copying write */
581 		ret = (long) bio_nwrite(bio, ptr, (size_t) num);
582 		break;
583 
584 
585 		/* standard CTRL codes follow */
586 
587 	case BIO_CTRL_RESET:
588 		if (b->buf != NULL) {
589 			b->len = 0;
590 			b->offset = 0;
591 		}
592 		ret = 0;
593 		break;
594 
595 
596 	case BIO_CTRL_GET_CLOSE:
597 		ret = bio->shutdown;
598 		break;
599 
600 	case BIO_CTRL_SET_CLOSE:
601 		bio->shutdown = (int) num;
602 		ret = 1;
603 		break;
604 
605 	case BIO_CTRL_PENDING:
606 		if (b->peer != NULL) {
607 			struct bio_bio_st *peer_b = b->peer->ptr;
608 
609 			ret = (long) peer_b->len;
610 		} else
611 			ret = 0;
612 		break;
613 
614 	case BIO_CTRL_WPENDING:
615 		if (b->buf != NULL)
616 			ret = (long) b->len;
617 		else
618 			ret = 0;
619 		break;
620 
621 	case BIO_CTRL_DUP:
622 		/* See BIO_dup_chain for circumstances we have to expect. */
623 		{
624 			BIO *other_bio = ptr;
625 			struct bio_bio_st *other_b;
626 
627 			assert(other_bio != NULL);
628 			other_b = other_bio->ptr;
629 			assert(other_b != NULL);
630 
631 			assert(other_b->buf == NULL); /* other_bio is always fresh */
632 
633 			other_b->size = b->size;
634 		}
635 
636 		ret = 1;
637 		break;
638 
639 	case BIO_CTRL_FLUSH:
640 		ret = 1;
641 		break;
642 
643 	case BIO_CTRL_EOF:
644 		{
645 			BIO *other_bio = ptr;
646 
647 			if (other_bio) {
648 				struct bio_bio_st *other_b = other_bio->ptr;
649 
650 				assert(other_b != NULL);
651 				ret = other_b->len == 0 && other_b->closed;
652 			} else
653 				ret = 1;
654 		}
655 		break;
656 
657 	default:
658 		ret = 0;
659 	}
660 	return ret;
661 }
662 
663 static int
664 bio_puts(BIO *bio, const char *str)
665 {
666 	return bio_write(bio, str, strlen(str));
667 }
668 
669 
670 static int
671 bio_make_pair(BIO *bio1, BIO *bio2)
672 {
673 	struct bio_bio_st *b1, *b2;
674 
675 	assert(bio1 != NULL);
676 	assert(bio2 != NULL);
677 
678 	b1 = bio1->ptr;
679 	b2 = bio2->ptr;
680 
681 	if (b1->peer != NULL || b2->peer != NULL) {
682 		BIOerr(BIO_F_BIO_MAKE_PAIR, BIO_R_IN_USE);
683 		return 0;
684 	}
685 
686 	if (b1->buf == NULL) {
687 		b1->buf = malloc(b1->size);
688 		if (b1->buf == NULL) {
689 			BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
690 			return 0;
691 		}
692 		b1->len = 0;
693 		b1->offset = 0;
694 	}
695 
696 	if (b2->buf == NULL) {
697 		b2->buf = malloc(b2->size);
698 		if (b2->buf == NULL) {
699 			BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
700 			return 0;
701 		}
702 		b2->len = 0;
703 		b2->offset = 0;
704 	}
705 
706 	b1->peer = bio2;
707 	b1->closed = 0;
708 	b1->request = 0;
709 	b2->peer = bio1;
710 	b2->closed = 0;
711 	b2->request = 0;
712 
713 	bio1->init = 1;
714 	bio2->init = 1;
715 
716 	return 1;
717 }
718 
719 static void
720 bio_destroy_pair(BIO *bio)
721 {
722 	struct bio_bio_st *b = bio->ptr;
723 
724 	if (b != NULL) {
725 		BIO *peer_bio = b->peer;
726 
727 		if (peer_bio != NULL) {
728 			struct bio_bio_st *peer_b = peer_bio->ptr;
729 
730 			assert(peer_b != NULL);
731 			assert(peer_b->peer == bio);
732 
733 			peer_b->peer = NULL;
734 			peer_bio->init = 0;
735 			assert(peer_b->buf != NULL);
736 			peer_b->len = 0;
737 			peer_b->offset = 0;
738 
739 			b->peer = NULL;
740 			bio->init = 0;
741 			assert(b->buf != NULL);
742 			b->len = 0;
743 			b->offset = 0;
744 		}
745 	}
746 }
747 
748 
749 /* Exported convenience functions */
750 int
751 BIO_new_bio_pair(BIO **bio1_p, size_t writebuf1, BIO **bio2_p, size_t writebuf2)
752 {
753 	BIO *bio1 = NULL, *bio2 = NULL;
754 	long r;
755 	int ret = 0;
756 
757 	bio1 = BIO_new(BIO_s_bio());
758 	if (bio1 == NULL)
759 		goto err;
760 	bio2 = BIO_new(BIO_s_bio());
761 	if (bio2 == NULL)
762 		goto err;
763 
764 	if (writebuf1) {
765 		r = BIO_set_write_buf_size(bio1, writebuf1);
766 		if (!r)
767 			goto err;
768 	}
769 	if (writebuf2) {
770 		r = BIO_set_write_buf_size(bio2, writebuf2);
771 		if (!r)
772 			goto err;
773 	}
774 
775 	r = BIO_make_bio_pair(bio1, bio2);
776 	if (!r)
777 		goto err;
778 	ret = 1;
779 
780 	err:
781 	if (ret == 0) {
782 		if (bio1) {
783 			BIO_free(bio1);
784 			bio1 = NULL;
785 		}
786 		if (bio2) {
787 			BIO_free(bio2);
788 			bio2 = NULL;
789 		}
790 	}
791 
792 	*bio1_p = bio1;
793 	*bio2_p = bio2;
794 	return ret;
795 }
796 
797 size_t
798 BIO_ctrl_get_write_guarantee(BIO *bio)
799 {
800 	return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL);
801 }
802 
803 size_t
804 BIO_ctrl_get_read_request(BIO *bio)
805 {
806 	return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL);
807 }
808 
809 int
810 BIO_ctrl_reset_read_request(BIO *bio)
811 {
812 	return (BIO_ctrl(bio, BIO_C_RESET_READ_REQUEST, 0, NULL) != 0);
813 }
814 
815 
816 /* BIO_nread0/nread/nwrite0/nwrite are available only for BIO pairs for now
817  * (conceivably some other BIOs could allow non-copying reads and writes too.)
818  */
819 int
820 BIO_nread0(BIO *bio, char **buf)
821 {
822 	long ret;
823 
824 	if (!bio->init) {
825 		BIOerr(BIO_F_BIO_NREAD0, BIO_R_UNINITIALIZED);
826 		return -2;
827 	}
828 
829 	ret = BIO_ctrl(bio, BIO_C_NREAD0, 0, buf);
830 	if (ret > INT_MAX)
831 		return INT_MAX;
832 	else
833 		return (int) ret;
834 }
835 
836 int
837 BIO_nread(BIO *bio, char **buf, int num)
838 {
839 	int ret;
840 
841 	if (!bio->init) {
842 		BIOerr(BIO_F_BIO_NREAD, BIO_R_UNINITIALIZED);
843 		return -2;
844 	}
845 
846 	ret = (int) BIO_ctrl(bio, BIO_C_NREAD, num, buf);
847 	if (ret > 0)
848 		bio->num_read += ret;
849 	return ret;
850 }
851 
852 int
853 BIO_nwrite0(BIO *bio, char **buf)
854 {
855 	long ret;
856 
857 	if (!bio->init) {
858 		BIOerr(BIO_F_BIO_NWRITE0, BIO_R_UNINITIALIZED);
859 		return -2;
860 	}
861 
862 	ret = BIO_ctrl(bio, BIO_C_NWRITE0, 0, buf);
863 	if (ret > INT_MAX)
864 		return INT_MAX;
865 	else
866 		return (int) ret;
867 }
868 
869 int
870 BIO_nwrite(BIO *bio, char **buf, int num)
871 {
872 	int ret;
873 
874 	if (!bio->init) {
875 		BIOerr(BIO_F_BIO_NWRITE, BIO_R_UNINITIALIZED);
876 		return -2;
877 	}
878 
879 	ret = BIO_ctrl(bio, BIO_C_NWRITE, num, buf);
880 	if (ret > 0)
881 		bio->num_write += ret;
882 	return ret;
883 }
884