2 * Copyright 1999-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 * Special method for a BIO where the other endpoint is also a BIO of this
12 * kind, handled by the same thread (i.e. the "peer" is actually ourselves,
13 * wearing a different hat). Such "BIO pairs" are mainly for using the SSL
14 * library with I/O interfaces for which no specific BIO method is available.
15 * See ssl/ssltest.c for some hints on how this can be used.
24 #include <openssl/err.h>
25 #include <openssl/crypto.h>
29 static int bio_new(BIO
*bio
);
30 static int bio_free(BIO
*bio
);
31 static int bio_read(BIO
*bio
, char *buf
, int size
);
32 static int bio_write(BIO
*bio
, const char *buf
, int num
);
33 static long bio_ctrl(BIO
*bio
, int cmd
, long num
, void *ptr
);
34 static int bio_puts(BIO
*bio
, const char *str
);
36 static int bio_make_pair(BIO
*bio1
, BIO
*bio2
);
37 static void bio_destroy_pair(BIO
*bio
);
39 static const BIO_METHOD methods_biop
= {
43 /* TODO: Convert to new style read function */
47 NULL
/* no bio_gets */ ,
51 NULL
/* no bio_callback_ctrl */
54 const BIO_METHOD
*BIO_s_bio(void)
60 BIO
*peer
; /* NULL if buf == NULL. If peer != NULL, then
61 * peer->ptr is also a bio_bio_st, and its
62 * "peer" member points back to us. peer !=
63 * NULL iff init != 0 in the BIO. */
64 /* This is for what we write (i.e. reading uses peer's struct): */
65 int closed
; /* valid iff peer != NULL */
66 size_t len
; /* valid iff buf != NULL; 0 if peer == NULL */
67 size_t offset
; /* valid iff buf != NULL; 0 if len == 0 */
69 char *buf
; /* "size" elements (if != NULL) */
70 size_t request
; /* valid iff peer != NULL; 0 if len != 0,
71 * otherwise set by peer to number of bytes
72 * it (unsuccessfully) tried to read, never
73 * more than buffer space (size-len)
77 static int bio_new(BIO
*bio
)
79 struct bio_bio_st
*b
= OPENSSL_zalloc(sizeof(*b
));
84 /* enough for one TLS record (just a default) */
91 static int bio_free(BIO
*bio
)
102 bio_destroy_pair(bio
);
104 OPENSSL_free(b
->buf
);
110 static int bio_read(BIO
*bio
, char *buf
, int size_
)
114 struct bio_bio_st
*b
, *peer_b
;
116 BIO_clear_retry_flags(bio
);
123 assert(b
->peer
!= NULL
);
124 peer_b
= b
->peer
->ptr
;
125 assert(peer_b
!= NULL
);
126 assert(peer_b
->buf
!= NULL
);
128 peer_b
->request
= 0; /* will be set in "retry_read" situation */
130 if (buf
== NULL
|| size
== 0)
133 if (peer_b
->len
== 0) {
135 return 0; /* writer has closed, and no data is left */
137 BIO_set_retry_read(bio
); /* buffer is empty */
138 if (size
<= peer_b
->size
)
139 peer_b
->request
= size
;
142 * don't ask for more than the peer can deliver in one write
144 peer_b
->request
= peer_b
->size
;
150 if (peer_b
->len
< size
)
153 /* now read "size" bytes */
158 do { /* one or two iterations */
161 assert(rest
<= peer_b
->len
);
162 if (peer_b
->offset
+ rest
<= peer_b
->size
)
165 /* wrap around ring buffer */
166 chunk
= peer_b
->size
- peer_b
->offset
;
167 assert(peer_b
->offset
+ chunk
<= peer_b
->size
);
169 memcpy(buf
, peer_b
->buf
+ peer_b
->offset
, chunk
);
171 peer_b
->len
-= chunk
;
173 peer_b
->offset
+= chunk
;
174 assert(peer_b
->offset
<= peer_b
->size
);
175 if (peer_b
->offset
== peer_b
->size
)
179 /* buffer now empty, no need to advance "buf" */
180 assert(chunk
== rest
);
191 * non-copying interface: provide pointer to available data in buffer
192 * bio_nread0: return number of available bytes
193 * bio_nread: also advance index
194 * (example usage: bio_nread0(), read from buffer, bio_nread()
195 * or just bio_nread(), read from buffer)
198 * WARNING: The non-copying interface is largely untested as of yet and may
201 static ossl_ssize_t
bio_nread0(BIO
*bio
, char **buf
)
203 struct bio_bio_st
*b
, *peer_b
;
206 BIO_clear_retry_flags(bio
);
213 assert(b
->peer
!= NULL
);
214 peer_b
= b
->peer
->ptr
;
215 assert(peer_b
!= NULL
);
216 assert(peer_b
->buf
!= NULL
);
220 if (peer_b
->len
== 0) {
223 /* avoid code duplication -- nothing available for reading */
224 return bio_read(bio
, &dummy
, 1); /* returns 0 or -1 */
228 if (peer_b
->size
< peer_b
->offset
+ num
)
229 /* no ring buffer wrap-around for non-copying interface */
230 num
= peer_b
->size
- peer_b
->offset
;
234 *buf
= peer_b
->buf
+ peer_b
->offset
;
238 static ossl_ssize_t
bio_nread(BIO
*bio
, char **buf
, size_t num_
)
240 struct bio_bio_st
*b
, *peer_b
;
241 ossl_ssize_t num
, available
;
243 if (num_
> OSSL_SSIZE_MAX
)
244 num
= OSSL_SSIZE_MAX
;
246 num
= (ossl_ssize_t
) num_
;
248 available
= bio_nread0(bio
, buf
);
255 peer_b
= b
->peer
->ptr
;
259 peer_b
->offset
+= num
;
260 assert(peer_b
->offset
<= peer_b
->size
);
261 if (peer_b
->offset
== peer_b
->size
)
269 static int bio_write(BIO
*bio
, const char *buf
, int num_
)
273 struct bio_bio_st
*b
;
275 BIO_clear_retry_flags(bio
);
277 if (!bio
->init
|| buf
== NULL
|| num
== 0)
282 assert(b
->peer
!= NULL
);
283 assert(b
->buf
!= NULL
);
287 /* we already closed */
288 BIOerr(BIO_F_BIO_WRITE
, BIO_R_BROKEN_PIPE
);
292 assert(b
->len
<= b
->size
);
294 if (b
->len
== b
->size
) {
295 BIO_set_retry_write(bio
); /* buffer is full */
300 if (num
> b
->size
- b
->len
)
301 num
= b
->size
- b
->len
;
303 /* now write "num" bytes */
308 do { /* one or two iterations */
312 assert(b
->len
+ rest
<= b
->size
);
314 write_offset
= b
->offset
+ b
->len
;
315 if (write_offset
>= b
->size
)
316 write_offset
-= b
->size
;
317 /* b->buf[write_offset] is the first byte we can write to. */
319 if (write_offset
+ rest
<= b
->size
)
322 /* wrap around ring buffer */
323 chunk
= b
->size
- write_offset
;
325 memcpy(b
->buf
+ write_offset
, buf
, chunk
);
329 assert(b
->len
<= b
->size
);
340 * non-copying interface: provide pointer to region to write to
341 * bio_nwrite0: check how much space is available
342 * bio_nwrite: also increase length
343 * (example usage: bio_nwrite0(), write to buffer, bio_nwrite()
344 * or just bio_nwrite(), write to buffer)
346 static ossl_ssize_t
bio_nwrite0(BIO
*bio
, char **buf
)
348 struct bio_bio_st
*b
;
352 BIO_clear_retry_flags(bio
);
359 assert(b
->peer
!= NULL
);
360 assert(b
->buf
!= NULL
);
364 BIOerr(BIO_F_BIO_NWRITE0
, BIO_R_BROKEN_PIPE
);
368 assert(b
->len
<= b
->size
);
370 if (b
->len
== b
->size
) {
371 BIO_set_retry_write(bio
);
375 num
= b
->size
- b
->len
;
376 write_offset
= b
->offset
+ b
->len
;
377 if (write_offset
>= b
->size
)
378 write_offset
-= b
->size
;
379 if (write_offset
+ num
> b
->size
)
381 * no ring buffer wrap-around for non-copying interface (to fulfil
382 * the promise by BIO_ctrl_get_write_guarantee, BIO_nwrite may have
383 * to be called twice)
385 num
= b
->size
- write_offset
;
388 *buf
= b
->buf
+ write_offset
;
389 assert(write_offset
+ num
<= b
->size
);
394 static ossl_ssize_t
bio_nwrite(BIO
*bio
, char **buf
, size_t num_
)
396 struct bio_bio_st
*b
;
397 ossl_ssize_t num
, space
;
399 if (num_
> OSSL_SSIZE_MAX
)
400 num
= OSSL_SSIZE_MAX
;
402 num
= (ossl_ssize_t
) num_
;
404 space
= bio_nwrite0(bio
, buf
);
412 assert(b
->len
<= b
->size
);
417 static long bio_ctrl(BIO
*bio
, int cmd
, long num
, void *ptr
)
420 struct bio_bio_st
*b
= bio
->ptr
;
425 /* specific CTRL codes */
427 case BIO_C_SET_WRITE_BUF_SIZE
:
429 BIOerr(BIO_F_BIO_CTRL
, BIO_R_IN_USE
);
431 } else if (num
== 0) {
432 BIOerr(BIO_F_BIO_CTRL
, BIO_R_INVALID_ARGUMENT
);
435 size_t new_size
= num
;
437 if (b
->size
!= new_size
) {
438 OPENSSL_free(b
->buf
);
446 case BIO_C_GET_WRITE_BUF_SIZE
:
450 case BIO_C_MAKE_BIO_PAIR
:
452 BIO
*other_bio
= ptr
;
454 if (bio_make_pair(bio
, other_bio
))
461 case BIO_C_DESTROY_BIO_PAIR
:
463 * Affects both BIOs in the pair -- call just once! Or let
464 * BIO_free(bio1); BIO_free(bio2); do the job.
466 bio_destroy_pair(bio
);
470 case BIO_C_GET_WRITE_GUARANTEE
:
472 * How many bytes can the caller feed to the next write without
473 * having to keep any?
475 if (b
->peer
== NULL
|| b
->closed
)
478 ret
= (long)b
->size
- b
->len
;
481 case BIO_C_GET_READ_REQUEST
:
483 * If the peer unsuccessfully tried to read, how many bytes were
484 * requested? (As with BIO_CTRL_PENDING, that number can usually be
485 * treated as boolean.)
487 ret
= (long)b
->request
;
490 case BIO_C_RESET_READ_REQUEST
:
492 * Reset request. (Can be useful after read attempts at the other
493 * side that are meant to be non-blocking, e.g. when probing SSL_read
494 * to see if any data is available.)
500 case BIO_C_SHUTDOWN_WR
:
501 /* similar to shutdown(..., SHUT_WR) */
507 /* prepare for non-copying read */
508 ret
= (long)bio_nread0(bio
, ptr
);
512 /* non-copying read */
513 ret
= (long)bio_nread(bio
, ptr
, (size_t)num
);
517 /* prepare for non-copying write */
518 ret
= (long)bio_nwrite0(bio
, ptr
);
522 /* non-copying write */
523 ret
= (long)bio_nwrite(bio
, ptr
, (size_t)num
);
526 /* standard CTRL codes follow */
529 if (b
->buf
!= NULL
) {
536 case BIO_CTRL_GET_CLOSE
:
540 case BIO_CTRL_SET_CLOSE
:
541 bio
->shutdown
= (int)num
;
545 case BIO_CTRL_PENDING
:
546 if (b
->peer
!= NULL
) {
547 struct bio_bio_st
*peer_b
= b
->peer
->ptr
;
549 ret
= (long)peer_b
->len
;
554 case BIO_CTRL_WPENDING
:
562 /* See BIO_dup_chain for circumstances we have to expect. */
564 BIO
*other_bio
= ptr
;
565 struct bio_bio_st
*other_b
;
567 assert(other_bio
!= NULL
);
568 other_b
= other_bio
->ptr
;
569 assert(other_b
!= NULL
);
571 assert(other_b
->buf
== NULL
); /* other_bio is always fresh */
573 other_b
->size
= b
->size
;
584 if (b
->peer
!= NULL
) {
585 struct bio_bio_st
*peer_b
= b
->peer
->ptr
;
587 if (peer_b
->len
== 0 && peer_b
->closed
)
602 static int bio_puts(BIO
*bio
, const char *str
)
604 return bio_write(bio
, str
, strlen(str
));
607 static int bio_make_pair(BIO
*bio1
, BIO
*bio2
)
609 struct bio_bio_st
*b1
, *b2
;
611 assert(bio1
!= NULL
);
612 assert(bio2
!= NULL
);
617 if (b1
->peer
!= NULL
|| b2
->peer
!= NULL
) {
618 BIOerr(BIO_F_BIO_MAKE_PAIR
, BIO_R_IN_USE
);
622 if (b1
->buf
== NULL
) {
623 b1
->buf
= OPENSSL_malloc(b1
->size
);
624 if (b1
->buf
== NULL
) {
625 BIOerr(BIO_F_BIO_MAKE_PAIR
, ERR_R_MALLOC_FAILURE
);
632 if (b2
->buf
== NULL
) {
633 b2
->buf
= OPENSSL_malloc(b2
->size
);
634 if (b2
->buf
== NULL
) {
635 BIOerr(BIO_F_BIO_MAKE_PAIR
, ERR_R_MALLOC_FAILURE
);
655 static void bio_destroy_pair(BIO
*bio
)
657 struct bio_bio_st
*b
= bio
->ptr
;
660 BIO
*peer_bio
= b
->peer
;
662 if (peer_bio
!= NULL
) {
663 struct bio_bio_st
*peer_b
= peer_bio
->ptr
;
665 assert(peer_b
!= NULL
);
666 assert(peer_b
->peer
== bio
);
670 assert(peer_b
->buf
!= NULL
);
676 assert(b
->buf
!= NULL
);
683 /* Exported convenience functions */
684 int BIO_new_bio_pair(BIO
**bio1_p
, size_t writebuf1
,
685 BIO
**bio2_p
, size_t writebuf2
)
687 BIO
*bio1
= NULL
, *bio2
= NULL
;
691 bio1
= BIO_new(BIO_s_bio());
694 bio2
= BIO_new(BIO_s_bio());
699 r
= BIO_set_write_buf_size(bio1
, writebuf1
);
704 r
= BIO_set_write_buf_size(bio2
, writebuf2
);
709 r
= BIO_make_bio_pair(bio1
, bio2
);
727 size_t BIO_ctrl_get_write_guarantee(BIO
*bio
)
729 return BIO_ctrl(bio
, BIO_C_GET_WRITE_GUARANTEE
, 0, NULL
);
732 size_t BIO_ctrl_get_read_request(BIO
*bio
)
734 return BIO_ctrl(bio
, BIO_C_GET_READ_REQUEST
, 0, NULL
);
737 int BIO_ctrl_reset_read_request(BIO
*bio
)
739 return (BIO_ctrl(bio
, BIO_C_RESET_READ_REQUEST
, 0, NULL
) != 0);
743 * BIO_nread0/nread/nwrite0/nwrite are available only for BIO pairs for now
744 * (conceivably some other BIOs could allow non-copying reads and writes
747 int BIO_nread0(BIO
*bio
, char **buf
)
752 BIOerr(BIO_F_BIO_NREAD0
, BIO_R_UNINITIALIZED
);
756 ret
= BIO_ctrl(bio
, BIO_C_NREAD0
, 0, buf
);
763 int BIO_nread(BIO
*bio
, char **buf
, int num
)
768 BIOerr(BIO_F_BIO_NREAD
, BIO_R_UNINITIALIZED
);
772 ret
= (int)BIO_ctrl(bio
, BIO_C_NREAD
, num
, buf
);
774 bio
->num_read
+= ret
;
778 int BIO_nwrite0(BIO
*bio
, char **buf
)
783 BIOerr(BIO_F_BIO_NWRITE0
, BIO_R_UNINITIALIZED
);
787 ret
= BIO_ctrl(bio
, BIO_C_NWRITE0
, 0, buf
);
794 int BIO_nwrite(BIO
*bio
, char **buf
, int num
)
799 BIOerr(BIO_F_BIO_NWRITE
, BIO_R_UNINITIALIZED
);
803 ret
= BIO_ctrl(bio
, BIO_C_NWRITE
, num
, buf
);
805 bio
->num_write
+= ret
;