1 /* crypto/bio/bss_bio.c -*- Mode: C; c-file-style: "eay" -*- */
2 /* ====================================================================
3 * Copyright (c) 1998-2003 The OpenSSL Project. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
31 * 6. Redistributions of any form whatsoever must retain the following
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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 * ====================================================================
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).
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. */
63 /* BIO_DEBUG implies BIO_PAIR_DEBUG */
65 # ifndef BIO_PAIR_DEBUG
66 # define BIO_PAIR_DEBUG
70 /* disable assert() unless BIO_PAIR_DEBUG has been defined */
71 #ifndef BIO_PAIR_DEBUG
82 #include <openssl/bio.h>
83 #include <openssl/err.h>
84 #include <openssl/crypto.h>
88 /* VxWorks defines SSIZE_MAX with an empty value causing compile errors */
89 #if defined(OPENSSL_SYS_VXWORKS)
93 # define SSIZE_MAX INT_MAX
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);
103 static int bio_make_pair(BIO *bio1, BIO *bio2);
104 static void bio_destroy_pair(BIO *bio);
106 static BIO_METHOD methods_biop =
113 NULL /* no bio_gets */,
117 NULL /* no bio_callback_ctrl */
120 BIO_METHOD *BIO_s_bio(void)
122 return &methods_biop;
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. */
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 */
137 char *buf; /* "size" elements (if != NULL) */
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. */
145 static int bio_new(BIO *bio)
147 struct bio_bio_st *b;
149 b = OPENSSL_malloc(sizeof *b);
154 b->size = 17*1024; /* enough for one TLS record (just a default) */
162 static int bio_free(BIO *bio)
164 struct bio_bio_st *b;
173 bio_destroy_pair(bio);
177 OPENSSL_free(b->buf);
187 static int bio_read(BIO *bio, char *buf, int size_)
191 struct bio_bio_st *b, *peer_b;
193 BIO_clear_retry_flags(bio);
200 assert(b->peer != NULL);
201 peer_b = b->peer->ptr;
202 assert(peer_b != NULL);
203 assert(peer_b->buf != NULL);
205 peer_b->request = 0; /* will be set in "retry_read" situation */
207 if (buf == NULL || size == 0)
210 if (peer_b->len == 0)
213 return 0; /* writer has closed, and no data is left */
216 BIO_set_retry_read(bio); /* buffer is empty */
217 if (size <= peer_b->size)
218 peer_b->request = size;
220 /* don't ask for more than the peer can
221 * deliver in one write */
222 peer_b->request = peer_b->size;
228 if (peer_b->len < size)
231 /* now read "size" bytes */
236 do /* one or two iterations */
240 assert(rest <= peer_b->len);
241 if (peer_b->offset + rest <= peer_b->size)
244 /* wrap around ring buffer */
245 chunk = peer_b->size - peer_b->offset;
246 assert(peer_b->offset + chunk <= peer_b->size);
248 memcpy(buf, peer_b->buf + peer_b->offset, chunk);
250 peer_b->len -= chunk;
253 peer_b->offset += chunk;
254 assert(peer_b->offset <= peer_b->size);
255 if (peer_b->offset == peer_b->size)
261 /* buffer now empty, no need to advance "buf" */
262 assert(chunk == rest);
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)
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)
282 struct bio_bio_st *b, *peer_b;
285 BIO_clear_retry_flags(bio);
292 assert(b->peer != NULL);
293 peer_b = b->peer->ptr;
294 assert(peer_b != NULL);
295 assert(peer_b->buf != NULL);
299 if (peer_b->len == 0)
303 /* avoid code duplication -- nothing available for reading */
304 return bio_read(bio, &dummy, 1); /* returns 0 or -1 */
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;
314 *buf = peer_b->buf + peer_b->offset;
318 static ossl_ssize_t bio_nread(BIO *bio, char **buf, size_t num_)
320 struct bio_bio_st *b, *peer_b;
321 ossl_ssize_t num, available;
323 if (num_ > SSIZE_MAX)
326 num = (ossl_ssize_t)num_;
328 available = bio_nread0(bio, buf);
335 peer_b = b->peer->ptr;
340 peer_b->offset += num;
341 assert(peer_b->offset <= peer_b->size);
342 if (peer_b->offset == peer_b->size)
352 static int bio_write(BIO *bio, const char *buf, int num_)
356 struct bio_bio_st *b;
358 BIO_clear_retry_flags(bio);
360 if (!bio->init || buf == NULL || num == 0)
365 assert(b->peer != NULL);
366 assert(b->buf != NULL);
371 /* we already closed */
372 BIOerr(BIO_F_BIO_WRITE, BIO_R_BROKEN_PIPE);
376 assert(b->len <= b->size);
378 if (b->len == b->size)
380 BIO_set_retry_write(bio); /* buffer is full */
385 if (num > b->size - b->len)
386 num = b->size - b->len;
388 /* now write "num" bytes */
393 do /* one or two iterations */
398 assert(b->len + rest <= b->size);
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. */
405 if (write_offset + rest <= b->size)
408 /* wrap around ring buffer */
409 chunk = b->size - write_offset;
411 memcpy(b->buf + write_offset, buf, chunk);
415 assert(b->len <= b->size);
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)
431 static ossl_ssize_t bio_nwrite0(BIO *bio, char **buf)
433 struct bio_bio_st *b;
437 BIO_clear_retry_flags(bio);
444 assert(b->peer != NULL);
445 assert(b->buf != NULL);
450 BIOerr(BIO_F_BIO_NWRITE0, BIO_R_BROKEN_PIPE);
454 assert(b->len <= b->size);
456 if (b->len == b->size)
458 BIO_set_retry_write(bio);
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;
473 *buf = b->buf + write_offset;
474 assert(write_offset + num <= b->size);
479 static ossl_ssize_t bio_nwrite(BIO *bio, char **buf, size_t num_)
481 struct bio_bio_st *b;
482 ossl_ssize_t num, space;
484 if (num_ > SSIZE_MAX)
487 num = (ossl_ssize_t)num_;
489 space = bio_nwrite0(bio, buf);
497 assert(b->len <= b->size);
503 static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr)
506 struct bio_bio_st *b = bio->ptr;
512 /* specific CTRL codes */
514 case BIO_C_SET_WRITE_BUF_SIZE:
517 BIOerr(BIO_F_BIO_CTRL, BIO_R_IN_USE);
522 BIOerr(BIO_F_BIO_CTRL, BIO_R_INVALID_ARGUMENT);
527 size_t new_size = num;
529 if (b->size != new_size)
533 OPENSSL_free(b->buf);
542 case BIO_C_GET_WRITE_BUF_SIZE:
543 ret = (long) b->size;
546 case BIO_C_MAKE_BIO_PAIR:
548 BIO *other_bio = ptr;
550 if (bio_make_pair(bio, other_bio))
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);
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)
570 ret = (long) b->size - b->len;
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;
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
589 case BIO_C_SHUTDOWN_WR:
590 /* similar to shutdown(..., SHUT_WR) */
596 /* prepare for non-copying read */
597 ret = (long) bio_nread0(bio, ptr);
601 /* non-copying read */
602 ret = (long) bio_nread(bio, ptr, (size_t) num);
606 /* prepare for non-copying write */
607 ret = (long) bio_nwrite0(bio, ptr);
611 /* non-copying write */
612 ret = (long) bio_nwrite(bio, ptr, (size_t) num);
616 /* standard CTRL codes follow */
627 case BIO_CTRL_GET_CLOSE:
631 case BIO_CTRL_SET_CLOSE:
632 bio->shutdown = (int) num;
636 case BIO_CTRL_PENDING:
639 struct bio_bio_st *peer_b = b->peer->ptr;
641 ret = (long) peer_b->len;
647 case BIO_CTRL_WPENDING:
655 /* See BIO_dup_chain for circumstances we have to expect. */
657 BIO *other_bio = ptr;
658 struct bio_bio_st *other_b;
660 assert(other_bio != NULL);
661 other_b = other_bio->ptr;
662 assert(other_b != NULL);
664 assert(other_b->buf == NULL); /* other_bio is always fresh */
666 other_b->size = b->size;
678 BIO *other_bio = ptr;
682 struct bio_bio_st *other_b = other_bio->ptr;
684 assert(other_b != NULL);
685 ret = other_b->len == 0 && other_b->closed;
698 static int bio_puts(BIO *bio, const char *str)
700 return bio_write(bio, str, strlen(str));
704 static int bio_make_pair(BIO *bio1, BIO *bio2)
706 struct bio_bio_st *b1, *b2;
708 assert(bio1 != NULL);
709 assert(bio2 != NULL);
714 if (b1->peer != NULL || b2->peer != NULL)
716 BIOerr(BIO_F_BIO_MAKE_PAIR, BIO_R_IN_USE);
722 b1->buf = OPENSSL_malloc(b1->size);
725 BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
734 b2->buf = OPENSSL_malloc(b2->size);
737 BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
757 static void bio_destroy_pair(BIO *bio)
759 struct bio_bio_st *b = bio->ptr;
763 BIO *peer_bio = b->peer;
765 if (peer_bio != NULL)
767 struct bio_bio_st *peer_b = peer_bio->ptr;
769 assert(peer_b != NULL);
770 assert(peer_b->peer == bio);
774 assert(peer_b->buf != NULL);
780 assert(b->buf != NULL);
788 /* Exported convenience functions */
789 int BIO_new_bio_pair(BIO **bio1_p, size_t writebuf1,
790 BIO **bio2_p, size_t writebuf2)
792 BIO *bio1 = NULL, *bio2 = NULL;
796 bio1 = BIO_new(BIO_s_bio());
799 bio2 = BIO_new(BIO_s_bio());
805 r = BIO_set_write_buf_size(bio1, writebuf1);
811 r = BIO_set_write_buf_size(bio2, writebuf2);
816 r = BIO_make_bio_pair(bio1, bio2);
841 size_t BIO_ctrl_get_write_guarantee(BIO *bio)
843 return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL);
846 size_t BIO_ctrl_get_read_request(BIO *bio)
848 return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL);
851 int BIO_ctrl_reset_read_request(BIO *bio)
853 return (BIO_ctrl(bio, BIO_C_RESET_READ_REQUEST, 0, NULL) != 0);
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.)
860 int BIO_nread0(BIO *bio, char **buf)
866 BIOerr(BIO_F_BIO_NREAD0, BIO_R_UNINITIALIZED);
870 ret = BIO_ctrl(bio, BIO_C_NREAD0, 0, buf);
877 int BIO_nread(BIO *bio, char **buf, int num)
883 BIOerr(BIO_F_BIO_NREAD, BIO_R_UNINITIALIZED);
887 ret = (int) BIO_ctrl(bio, BIO_C_NREAD, num, buf);
889 bio->num_read += ret;
893 int BIO_nwrite0(BIO *bio, char **buf)
899 BIOerr(BIO_F_BIO_NWRITE0, BIO_R_UNINITIALIZED);
903 ret = BIO_ctrl(bio, BIO_C_NWRITE0, 0, buf);
910 int BIO_nwrite(BIO *bio, char **buf, int num)
916 BIOerr(BIO_F_BIO_NWRITE, BIO_R_UNINITIALIZED);
920 ret = BIO_ctrl(bio, BIO_C_NWRITE, num, buf);
922 bio->num_write += ret;