bio.h revision d9e397b599b13d642138480a28c14db7a136bf05
1/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2 * All rights reserved.
3 *
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
7 *
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to.  The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14 *
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the copyright
26 *    notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 *    notice, this list of conditions and the following disclaimer in the
29 *    documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 *    must display the following acknowledgement:
32 *    "This product includes cryptographic software written by
33 *     Eric Young (eay@cryptsoft.com)"
34 *    The word 'cryptographic' can be left out if the rouines from the library
35 *    being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 *    the apps directory (application code) you must include an acknowledgement:
38 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed.  i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.] */
56
57#ifndef OPENSSL_HEADER_BIO_H
58#define OPENSSL_HEADER_BIO_H
59
60#include <openssl/base.h>
61
62#include <stdarg.h>
63#include <stdio.h>  /* For FILE */
64
65#include <openssl/ex_data.h>
66#include <openssl/stack.h>
67
68#if defined(__cplusplus)
69extern "C" {
70#endif
71
72
73/* BIO abstracts over a file-descriptor like interface. */
74
75
76/* Allocation and freeing. */
77
78DEFINE_STACK_OF(BIO);
79
80/* BIO_new creates a new BIO with the given type and a reference count of one.
81 * It returns the fresh |BIO|, or NULL on error. */
82OPENSSL_EXPORT BIO *BIO_new(const BIO_METHOD *type);
83
84/* BIO_free decrements the reference count of |bio|. If the reference count
85 * drops to zero, it (optionally) calls the BIO's callback with |BIO_CB_FREE|,
86 * frees the ex_data and then, if the BIO has a destroy callback for the
87 * method, calls it. Finally it frees |bio| itself. It then repeats that for
88 * the next BIO in the chain, if any.
89 *
90 * It returns one on success or zero otherwise. */
91OPENSSL_EXPORT int BIO_free(BIO *bio);
92
93/* BIO_vfree performs the same actions as |BIO_free|, but has a void return
94 * value. This is provided for API-compat.
95 *
96 * TODO(fork): remove. */
97OPENSSL_EXPORT void BIO_vfree(BIO *bio);
98
99
100/* Basic I/O. */
101
102/* BIO_read attempts to read |len| bytes into |data|. It returns the number of
103 * bytes read, zero on EOF, or a negative number on error. */
104OPENSSL_EXPORT int BIO_read(BIO *bio, void *data, int len);
105
106/* BIO_gets "reads a line" from |bio| and puts at most |size| bytes into |buf|.
107 * It returns the number of bytes read or a negative number on error. The
108 * phrase "reads a line" is in quotes in the previous sentence because the
109 * exact operation depends on the BIO's method. For example, a digest BIO will
110 * return the digest in response to a |BIO_gets| call.
111 *
112 * TODO(fork): audit the set of BIOs that we end up needing. If all actually
113 * return a line for this call, remove the warning above. */
114OPENSSL_EXPORT int BIO_gets(BIO *bio, char *buf, int size);
115
116/* BIO_write writes |len| bytes from |data| to BIO. It returns the number of
117 * bytes written or a negative number on error. */
118OPENSSL_EXPORT int BIO_write(BIO *bio, const void *data, int len);
119
120/* BIO_puts writes a NUL terminated string from |buf| to |bio|. It returns the
121 * number of bytes written or a negative number on error. */
122OPENSSL_EXPORT int BIO_puts(BIO *bio, const char *buf);
123
124/* BIO_flush flushes any buffered output. It returns one on success and zero
125 * otherwise. */
126OPENSSL_EXPORT int BIO_flush(BIO *bio);
127
128
129/* Low-level control functions.
130 *
131 * These are generic functions for sending control requests to a BIO. In
132 * general one should use the wrapper functions like |BIO_get_close|. */
133
134/* BIO_ctrl sends the control request |cmd| to |bio|. The |cmd| argument should
135 * be one of the |BIO_C_*| values. */
136OPENSSL_EXPORT long BIO_ctrl(BIO *bio, int cmd, long larg, void *parg);
137
138/* BIO_ptr_ctrl acts like |BIO_ctrl| but passes the address of a |void*|
139 * pointer as |parg| and returns the value that is written to it, or NULL if
140 * the control request returns <= 0. */
141OPENSSL_EXPORT char *BIO_ptr_ctrl(BIO *bp, int cmd, long larg);
142
143/* BIO_int_ctrl acts like |BIO_ctrl| but passes the address of a copy of |iarg|
144 * as |parg|. */
145OPENSSL_EXPORT long BIO_int_ctrl(BIO *bp, int cmd, long larg, int iarg);
146
147/* BIO_reset resets |bio| to its initial state, the precise meaning of which
148 * depends on the concrete type of |bio|. It returns one on success and zero
149 * otherwise. */
150OPENSSL_EXPORT int BIO_reset(BIO *bio);
151
152/* BIO_set_flags ORs |flags| with |bio->flags|. */
153OPENSSL_EXPORT void BIO_set_flags(BIO *bio, int flags);
154
155/* BIO_test_flags returns |bio->flags| AND |flags|. */
156OPENSSL_EXPORT int BIO_test_flags(const BIO *bio, int flags);
157
158/* BIO_should_read returns non-zero if |bio| encountered a temporary error
159 * while reading (i.e. EAGAIN), indicating that the caller should retry the
160 * read. */
161OPENSSL_EXPORT int BIO_should_read(const BIO *bio);
162
163/* BIO_should_write returns non-zero if |bio| encountered a temporary error
164 * while writing (i.e. EAGAIN), indicating that the caller should retry the
165 * write. */
166OPENSSL_EXPORT int BIO_should_write(const BIO *bio);
167
168/* BIO_should_retry returns non-zero if the reason that caused a failed I/O
169 * operation is temporary and thus the operation should be retried. Otherwise,
170 * it was a permanent error and it returns zero. */
171OPENSSL_EXPORT int BIO_should_retry(const BIO *bio);
172
173/* BIO_should_io_special returns non-zero if |bio| encountered a temporary
174 * error while performing a special I/O operation, indicating that the caller
175 * should retry. The operation that caused the error is returned by
176 * |BIO_get_retry_reason|. */
177OPENSSL_EXPORT int BIO_should_io_special(const BIO *bio);
178
179/* BIO_RR_SSL_X509_LOOKUP indicates that an SSL BIO blocked because the SSL
180 * library returned with SSL_ERROR_WANT_X509_LOOKUP.
181 *
182 * TODO(fork): remove. */
183#define BIO_RR_SSL_X509_LOOKUP 0x01
184
185/* BIO_RR_CONNECT indicates that a connect would have blocked */
186#define BIO_RR_CONNECT 0x02
187
188/* BIO_RR_ACCEPT indicates that an accept would have blocked */
189#define BIO_RR_ACCEPT 0x03
190
191/* BIO_RR_SSL_CHANNEL_ID_LOOKUP indicates that the ChannelID code cannot find
192 * a private key for a TLS connection. */
193#define BIO_RR_SSL_CHANNEL_ID_LOOKUP 0x04
194
195/* BIO_get_retry_reason returns the special I/O operation that needs to be
196 * retried. The return value is one of the |BIO_RR_*| values. */
197OPENSSL_EXPORT int BIO_get_retry_reason(const BIO *bio);
198
199/* BIO_clear_flags ANDs |bio->flags| with the bitwise-complement of |flags|. */
200OPENSSL_EXPORT void BIO_clear_flags(BIO *bio, int flags);
201
202/* BIO_set_retry_read sets the |BIO_FLAGS_READ| and |BIO_FLAGS_SHOULD_RETRY|
203 * flags on |bio|. */
204OPENSSL_EXPORT void BIO_set_retry_read(BIO *bio);
205
206/* BIO_set_retry_read sets the |BIO_FLAGS_WRITE| and |BIO_FLAGS_SHOULD_RETRY|
207 * flags on |bio|. */
208OPENSSL_EXPORT void BIO_set_retry_write(BIO *bio);
209
210/* BIO_get_retry_flags gets the |BIO_FLAGS_READ|, |BIO_FLAGS_WRITE|,
211 * |BIO_FLAGS_IO_SPECIAL| and |BIO_FLAGS_SHOULD_RETRY| flags from |bio|. */
212OPENSSL_EXPORT int BIO_get_retry_flags(BIO *bio);
213
214/* BIO_clear_retry_flags clears the |BIO_FLAGS_READ|, |BIO_FLAGS_WRITE|,
215 * |BIO_FLAGS_IO_SPECIAL| and |BIO_FLAGS_SHOULD_RETRY| flags from |bio|. */
216OPENSSL_EXPORT void BIO_clear_retry_flags(BIO *bio);
217
218/* BIO_method_type returns the type of |bio|, which is one of the |BIO_TYPE_*|
219 * values. */
220OPENSSL_EXPORT int BIO_method_type(const BIO *bio);
221
222/* bio_info_cb is the type of a callback function that can be called for most
223 * BIO operations. The |event| argument is one of |BIO_CB_*| and can be ORed
224 * with |BIO_CB_RETURN| if the callback is being made after the operation in
225 * question. In that case, |return_value| will contain the return value from
226 * the operation. */
227typedef long (*bio_info_cb)(BIO *bio, int event, const char *parg, int cmd,
228                            long larg, long return_value);
229
230/* BIO_callback_ctrl allows the callback function to be manipulated. The |cmd|
231 * arg will generally be |BIO_CTRL_SET_CALLBACK| but arbitary command values
232 * can be interpreted by the |BIO|. */
233OPENSSL_EXPORT long BIO_callback_ctrl(BIO *bio, int cmd, bio_info_cb fp);
234
235/* BIO_pending returns the number of bytes pending to be read. */
236OPENSSL_EXPORT size_t BIO_pending(const BIO *bio);
237
238/* BIO_ctrl_pending calls |BIO_pending| and exists only for compatibility with
239 * OpenSSL. */
240OPENSSL_EXPORT size_t BIO_ctrl_pending(const BIO *bio);
241
242/* BIO_wpending returns the number of bytes pending to be written. */
243OPENSSL_EXPORT size_t BIO_wpending(const BIO *bio);
244
245/* BIO_set_close sets the close flag for |bio|. The meaning of which depends on
246 * the type of |bio| but, for example, a memory BIO interprets the close flag
247 * as meaning that it owns its buffer. It returns one on success and zero
248 * otherwise. */
249OPENSSL_EXPORT int BIO_set_close(BIO *bio, int close_flag);
250
251/* BIO_set_callback sets a callback function that will be called before and
252 * after most operations. See the comment above |bio_info_cb|. */
253OPENSSL_EXPORT void BIO_set_callback(BIO *bio, bio_info_cb callback_func);
254
255/* BIO_set_callback_arg sets the opaque pointer value that can be read within a
256 * callback with |BIO_get_callback_arg|. */
257OPENSSL_EXPORT void BIO_set_callback_arg(BIO *bio, char *arg);
258
259/* BIO_get_callback_arg returns the last value of the opaque callback pointer
260 * set by |BIO_set_callback_arg|. */
261OPENSSL_EXPORT char *BIO_get_callback_arg(const BIO *bio);
262
263/* BIO_number_read returns the number of bytes that have been read from
264 * |bio|. */
265OPENSSL_EXPORT size_t BIO_number_read(const BIO *bio);
266
267/* BIO_number_written returns the number of bytes that have been written to
268 * |bio|. */
269OPENSSL_EXPORT size_t BIO_number_written(const BIO *bio);
270
271
272/* Managing chains of BIOs.
273 *
274 * BIOs can be put into chains where the output of one is used as the input of
275 * the next etc. The most common case is a buffering BIO, which accepts and
276 * buffers writes until flushed into the next BIO in the chain. */
277
278/* BIO_push adds |appended_bio| to the end of the chain with |bio| at the head.
279 * It returns |bio|. Note that |appended_bio| may be the head of a chain itself
280 * and thus this function can be used to join two chains.
281 *
282 * BIO_push takes ownership of the caller's reference to |appended_bio|. */
283OPENSSL_EXPORT BIO *BIO_push(BIO *bio, BIO *appended_bio);
284
285/* BIO_pop removes |bio| from the head of a chain and returns the next BIO in
286 * the chain, or NULL if there is no next BIO.
287 *
288 * The caller takes ownership of the chain's reference to |bio|. */
289OPENSSL_EXPORT BIO *BIO_pop(BIO *bio);
290
291/* BIO_next returns the next BIO in the chain after |bio|, or NULL if there is
292 * no such BIO. */
293OPENSSL_EXPORT BIO *BIO_next(BIO *bio);
294
295/* BIO_free_all calls |BIO_free|.
296 *
297 * TODO(fork): update callers and remove. */
298OPENSSL_EXPORT void BIO_free_all(BIO *bio);
299
300/* BIO_find_type walks a chain of BIOs and returns the first that matches
301 * |type|, which is one of the |BIO_TYPE_*| values. */
302OPENSSL_EXPORT BIO *BIO_find_type(BIO *bio, int type);
303
304/* BIO_copy_next_retry sets the retry flags and |retry_reason| of |bio| from
305 * the next BIO in the chain. */
306OPENSSL_EXPORT void BIO_copy_next_retry(BIO *bio);
307
308
309/* Printf functions.
310 *
311 * These functions are versions of printf functions that output to a BIO rather
312 * than a FILE. */
313#ifdef __GNUC__
314#define __bio_h__attr__ __attribute__
315#else
316#define __bio_h__attr__(x)
317#endif
318OPENSSL_EXPORT int BIO_printf(BIO *bio, const char *format, ...)
319    __bio_h__attr__((__format__(__printf__, 2, 3)));
320#undef __bio_h__attr__
321
322
323/* Utility functions. */
324
325/* BIO_indent prints min(|indent|, |max_indent|) spaces. It returns one on
326 * success and zero otherwise. */
327OPENSSL_EXPORT int BIO_indent(BIO *bio, unsigned indent, unsigned max_indent);
328
329/* BIO_hexdump writes a hex dump of |data| to |bio|. Each line will be indented
330 * by |indent| spaces. */
331OPENSSL_EXPORT int BIO_hexdump(BIO *bio, const uint8_t *data, size_t len,
332                               unsigned indent);
333
334/* BIO_print_errors_fp prints the current contents of the error stack to |out|
335 * using human readable strings where possible. */
336OPENSSL_EXPORT void BIO_print_errors_fp(FILE *out);
337
338/* BIO_print_errors prints the current contents of the error stack to |bio|
339 * using human readable strings where possible. */
340OPENSSL_EXPORT void BIO_print_errors(BIO *bio);
341
342
343/* Memory BIOs.
344 *
345 * Memory BIOs can be used as a read-only source (with |BIO_new_mem_buf|) or a
346 * writable sink (with |BIO_new|, |BIO_s_mem| and |BIO_get_mem_buf|). Data
347 * written to a writable, memory BIO can be recalled by reading from it.
348 *
349 * Calling |BIO_reset| on a read-only BIO resets it to the original contents.
350 * On a writable BIO, it clears any data.
351 *
352 * If the close flag is set to |BIO_NOCLOSE| (not the default) then the
353 * underlying |BUF_MEM| will not be freed when the |BIO| is freed.
354 *
355 * Memory BIOs support |BIO_gets| and |BIO_puts|.
356 *
357 * |BIO_eof| is true if no data is in the BIO.
358 *
359 * |BIO_ctrl_pending| returns the number of bytes currently stored. */
360
361/* BIO_s_mem returns a |BIO_METHOD| that uses a in-memory buffer. */
362OPENSSL_EXPORT const BIO_METHOD *BIO_s_mem(void);
363
364/* BIO_new_mem_buf creates BIO that reads and writes from |len| bytes at |buf|.
365 * It does not take ownership of |buf|. It returns the BIO or NULL on error.
366 *
367 * If |len| is negative, then |buf| is treated as a NUL-terminated string, but
368 * don't depend on this in new code. */
369OPENSSL_EXPORT BIO *BIO_new_mem_buf(void *buf, int len);
370
371/* BIO_mem_contents sets |*out_contents| to point to the current contents of
372 * |bio| and |*out_len| to contain the length of that data. It returns one on
373 * success and zero otherwise. */
374OPENSSL_EXPORT int BIO_mem_contents(const BIO *bio,
375                                    const uint8_t **out_contents,
376                                    size_t *out_len);
377
378/* BIO_get_mem_data sets |*contents| to point to the current contents of |bio|
379 * and returns the length of the data.
380 *
381 * WARNING: don't use this, use |BIO_mem_contents|. A return value of zero from
382 * this function can mean either that it failed or that the memory buffer is
383 * empty. */
384OPENSSL_EXPORT long BIO_get_mem_data(BIO *bio, char **contents);
385
386/* BIO_get_mem_ptr sets |*out| to a BUF_MEM containing the current contents of
387 * |bio|. It returns one on success or zero on error. */
388OPENSSL_EXPORT int BIO_get_mem_ptr(BIO *bio, BUF_MEM **out);
389
390/* BIO_set_mem_buf sets |b| as the contents of |bio|. If |take_ownership| is
391 * non-zero, then |b| will be freed when |bio| is closed. Returns one on
392 * success or zero otherwise. */
393OPENSSL_EXPORT int BIO_set_mem_buf(BIO *bio, BUF_MEM *b, int take_ownership);
394
395/* BIO_set_mem_eof_return sets the value that will be returned from reading
396 * |bio| when empty. If |eof_value| is zero then an empty memory BIO will
397 * return EOF (that is it will return zero and |BIO_should_retry| will be
398 * false). If |eof_value| is non zero then it will return |eof_value| when it
399 * is empty and it will set the read retry flag (that is |BIO_read_retry| is
400 * true). To avoid ambiguity with a normal positive return value, |eof_value|
401 * should be set to a negative value, typically -1.
402 *
403 * For a read-only BIO, the default is zero (EOF). For a writable BIO, the
404 * default is -1 so that additional data can be written once exhausted. */
405OPENSSL_EXPORT int BIO_set_mem_eof_return(BIO *bio, int eof_value);
406
407
408/* File descriptor BIOs.
409 *
410 * File descriptor BIOs are wrappers around the system's |read| and |write|
411 * functions. If the close flag is set then then |close| is called on the
412 * underlying file descriptor when the BIO is freed.
413 *
414 * |BIO_reset| attempts to seek the file pointer to the start of file using
415 * |lseek|.
416 *
417 * |BIO_seek| sets the file pointer to position |off| from start of file using
418 * |lseek|.
419 *
420 * |BIO_tell| returns the current file position. */
421
422/* BIO_s_fd returns a |BIO_METHOD| for file descriptor fds. */
423OPENSSL_EXPORT const BIO_METHOD *BIO_s_fd(void);
424
425/* BIO_new_fd creates a new file descriptor BIO wrapping |fd|. If |close_flag|
426 * is non-zero, then |fd| will be closed when the BIO is. */
427OPENSSL_EXPORT BIO *BIO_new_fd(int fd, int close_flag);
428
429/* BIO_set_fd sets the file descriptor of |bio| to |fd|. If |close_flag| is
430 * non-zero then |fd| will be closed when |bio| is. It returns one on success
431 * or zero on error. */
432OPENSSL_EXPORT int BIO_set_fd(BIO *bio, int fd, int close_flag);
433
434/* BIO_get_fd sets |*out_fd| to the file descriptor currently in use by |bio|.
435 * It returns one on success and zero on error. */
436OPENSSL_EXPORT int BIO_get_fd(BIO *bio, int *out_fd);
437
438
439/* File BIOs.
440 *
441 * File BIOs are wrappers around a C |FILE| object.
442 *
443 * |BIO_flush| on a file BIO calls |fflush| on the wrapped stream.
444 *
445 * |BIO_reset| attempts to seek the file pointer to the start of file using
446 * |fseek|.
447 *
448 * |BIO_seek| sets the file pointer to the given position from the start of
449 * file using |fseek|.
450 *
451 * |BIO_eof| calls |feof|.
452 *
453 * Setting the close flag causes |fclose| to be called on the stream when the
454 * BIO is freed. */
455
456/* BIO_s_file returns a BIO_METHOD that wraps a |FILE|. */
457OPENSSL_EXPORT const BIO_METHOD *BIO_s_file(void);
458
459/* BIO_new_file creates a file BIO by opening |filename| with the given mode.
460 * See the |fopen| manual page for details of the mode argument. */
461OPENSSL_EXPORT BIO *BIO_new_file(const char *filename, const char *mode);
462
463/* BIO_new_fp creates a new file BIO that wraps the given |FILE|. If
464 * |close_flag| is |BIO_CLOSE|, then |fclose| will be called on |stream| when
465 * the BIO is closed. */
466OPENSSL_EXPORT BIO *BIO_new_fp(FILE *stream, int close_flag);
467
468/* BIO_get_fp sets |*out_file| to the current |FILE| for |bio|. It returns one
469 * on success and zero otherwise. */
470OPENSSL_EXPORT int BIO_get_fp(BIO *bio, FILE **out_file);
471
472/* BIO_set_fp sets the |FILE| for |bio|. If |close_flag| is |BIO_CLOSE| then
473 * |fclose| will be called on |file| when |bio| is closed. It returns one on
474 * sucess and zero otherwise. */
475OPENSSL_EXPORT int BIO_set_fp(BIO *bio, FILE *file, int close_flag);
476
477/* BIO_read_filename opens |filename| for reading and sets the result as the
478 * |FILE| for |bio|. It returns one on success and zero otherwise. The |FILE|
479 * will be closed when |bio| is freed. */
480OPENSSL_EXPORT int BIO_read_filename(BIO *bio, const char *filename);
481
482/* BIO_write_filename opens |filename| for writing and sets the result as the
483 * |FILE| for |bio|. It returns one on success and zero otherwise. The |FILE|
484 * will be closed when |bio| is freed. */
485OPENSSL_EXPORT int BIO_write_filename(BIO *bio, const char *filename);
486
487/* BIO_append_filename opens |filename| for appending and sets the result as
488 * the |FILE| for |bio|. It returns one on success and zero otherwise. The
489 * |FILE| will be closed when |bio| is freed. */
490OPENSSL_EXPORT int BIO_append_filename(BIO *bio, const char *filename);
491
492/* BIO_rw_filename opens |filename| for reading and writing and sets the result
493 * as the |FILE| for |bio|. It returns one on success and zero otherwise. The
494 * |FILE| will be closed when |bio| is freed. */
495OPENSSL_EXPORT int BIO_rw_filename(BIO *bio, const char *filename);
496
497
498/* Buffer BIOs.
499 *
500 * Buffer BIOs are a filter-type BIO, i.e. they are designed to be used in a
501 * chain of BIOs. They provide buffering to reduce the number of operations on
502 * the underlying BIOs. */
503
504OPENSSL_EXPORT const BIO_METHOD *BIO_f_buffer(void);
505
506/* BIO_set_read_buffer_size sets the size, in bytes, of the read buffer and
507 * clears it. It returns one on success and zero on failure. */
508OPENSSL_EXPORT int BIO_set_read_buffer_size(BIO *bio, int buffer_size);
509
510/* BIO_set_write_buffer_size sets the size, in bytes, of the write buffer and
511 * clears it. It returns one on success and zero on failure. */
512OPENSSL_EXPORT int BIO_set_write_buffer_size(BIO *bio, int buffer_size);
513
514
515/* Socket BIOs. */
516
517OPENSSL_EXPORT const BIO_METHOD *BIO_s_socket(void);
518
519/* BIO_new_socket allocates and initialises a fresh BIO which will read and
520 * write to the socket |fd|. If |close_flag| is |BIO_CLOSE| then closing the
521 * BIO will close |fd|. It returns the fresh |BIO| or NULL on error. */
522OPENSSL_EXPORT BIO *BIO_new_socket(int fd, int close_flag);
523
524
525/* Connect BIOs.
526 *
527 * A connection BIO creates a network connection and transfers data over the
528 * resulting socket. */
529
530OPENSSL_EXPORT const BIO_METHOD *BIO_s_connect(void);
531
532/* BIO_new_connect returns a BIO that connects to the given hostname and port.
533 * The |host_and_optional_port| argument should be of the form
534 * "www.example.com" or "www.example.com:443". If the port is omitted, it must
535 * be provided with |BIO_set_conn_port|.
536 *
537 * It returns the new BIO on success, or NULL on error. */
538OPENSSL_EXPORT BIO *BIO_new_connect(const char *host_and_optional_port);
539
540/* BIO_set_conn_hostname sets |host_and_optional_port| as the hostname and
541 * optional port that |bio| will connect to. If the port is omitted, it must be
542 * provided with |BIO_set_conn_port|.
543 *
544 * It returns one on success and zero otherwise. */
545OPENSSL_EXPORT int BIO_set_conn_hostname(BIO *bio,
546                                         const char *host_and_optional_port);
547
548/* BIO_set_conn_port sets |port_str| as the port or service name that |bio|
549 * will connect to. It returns one on success and zero otherwise. */
550OPENSSL_EXPORT int BIO_set_conn_port(BIO *bio, const char *port_str);
551
552/* BIO_set_nbio sets whether |bio| will use non-blocking I/O operations. It
553 * returns one on success and zero otherwise. */
554OPENSSL_EXPORT int BIO_set_nbio(BIO *bio, int on);
555
556
557/* Datagram BIOs.
558 *
559 * TODO(fork): not implemented. */
560
561#define BIO_CTRL_DGRAM_QUERY_MTU 40 /* as kernel for current MTU */
562
563#define BIO_CTRL_DGRAM_SET_MTU 42 /* set cached value for  MTU. want to use
564                                     this if asking the kernel fails */
565
566#define BIO_CTRL_DGRAM_MTU_EXCEEDED 43 /* check whether the MTU was exceed in
567                                          the previous write operation. */
568
569#define BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT \
570  45 /* Next DTLS handshake timeout to adjust socket timeouts */
571
572#define BIO_CTRL_DGRAM_GET_PEER           46
573
574#define BIO_CTRL_DGRAM_GET_FALLBACK_MTU   47
575
576
577/* BIO Pairs.
578 *
579 * BIO pairs provide a "loopback" like system: a pair of BIOs where data
580 * written to one can be read from the other and vice versa. */
581
582/* BIO_new_bio_pair sets |*out1| and |*out2| to two freshly created BIOs where
583 * data written to one can be read from the other and vice versa. The
584 * |writebuf1| argument gives the size of the buffer used in |*out1| and
585 * |writebuf2| for |*out2|. It returns one on success and zero on error. */
586OPENSSL_EXPORT int BIO_new_bio_pair(BIO **out1, size_t writebuf1, BIO **out2,
587                                    size_t writebuf2);
588
589/* BIO_new_bio_pair_external_buf is the same as |BIO_new_bio_pair| with the
590 * difference that the caller keeps ownership of the write buffers
591 * |ext_writebuf1_len| and |ext_writebuf2_len|. This is useful when using zero
592 * copy API for read and write operations, in cases where the buffers need to
593 * outlive the BIO pairs. It returns one on success and zero on error. */
594OPENSSL_EXPORT int BIO_new_bio_pair_external_buf(BIO** bio1_p,
595                                                 size_t writebuf1_len,
596                                                 uint8_t* ext_writebuf1,
597                                                 BIO** bio2_p,
598                                                 size_t writebuf2_len,
599                                                 uint8_t* ext_writebuf2);
600
601/* BIO_ctrl_get_read_request returns the number of bytes that the other side of
602 * |bio| tried (unsuccessfully) to read. */
603OPENSSL_EXPORT size_t BIO_ctrl_get_read_request(BIO *bio);
604
605/* BIO_ctrl_get_write_guarantee returns the number of bytes that |bio| (which
606 * must have been returned by |BIO_new_bio_pair|) will accept on the next
607 * |BIO_write| call. */
608OPENSSL_EXPORT size_t BIO_ctrl_get_write_guarantee(BIO *bio);
609
610/* BIO_shutdown_wr marks |bio| as closed, from the point of view of the other
611 * side of the pair. Future |BIO_write| calls on |bio| will fail. It returns
612 * one on success and zero otherwise. */
613OPENSSL_EXPORT int BIO_shutdown_wr(BIO *bio);
614
615
616/* Zero copy versions of BIO_read and BIO_write for BIO pairs. */
617
618/* BIO_zero_copy_get_read_buf initiates a zero copy read operation.
619 * |out_read_buf| is set to the internal read buffer, and |out_buf_offset| is
620 * set to the current read position of |out_read_buf|. The number of bytes
621 * available for read from |out_read_buf| + |out_buf_offset| is returned in
622 * |out_available_bytes|. Note that this function might report fewer bytes
623 * available than |BIO_pending|, if the internal ring buffer is wrapped. It
624 * returns one on success. In case of error it returns zero and pushes to the
625 * error stack.
626 *
627 * The zero copy read operation is completed by calling
628 * |BIO_zero_copy_get_read_buf_done|. Neither |BIO_zero_copy_get_read_buf| nor
629 * any other I/O read operation may be called while a zero copy read operation
630 * is active. */
631OPENSSL_EXPORT int BIO_zero_copy_get_read_buf(BIO* bio,
632                                              uint8_t** out_read_buf,
633                                              size_t* out_buf_offset,
634                                              size_t* out_available_bytes);
635
636/* BIO_zero_copy_get_read_buf_done must be called after reading from a BIO using
637 * |BIO_zero_copy_get_read_buf| to finish the read operation. The |bytes_read|
638 * argument is the number of bytes read.
639 *
640 * It returns one on success. In case of error it returns zero and pushes to the
641 * error stack. */
642OPENSSL_EXPORT int BIO_zero_copy_get_read_buf_done(BIO* bio, size_t bytes_read);
643
644/* BIO_zero_copy_get_write_buf_done initiates a zero copy write operation.
645 * |out_write_buf| is set to to the internal write buffer, and |out_buf_offset|
646 * is set to the current write position of |out_write_buf|.
647 * The number of bytes available for write from |out_write_buf| +
648 * |out_buf_offset| is returned in |out_available_bytes|. Note that this
649 * function might report fewer bytes available than
650 * |BIO_ctrl_get_write_guarantee|, if the internal buffer is wrapped. It returns
651 * one on success. In case of error it returns zero and pushes to the error
652 * stack.
653 *
654 * The zero copy write operation is completed by calling
655 * |BIO_zero_copy_write_buf_don|e. Neither |BIO_zero_copy_get_write_buf_done|
656 * nor any other I/O write operation may be called while a zero copy write
657 * operation is active. */
658OPENSSL_EXPORT int BIO_zero_copy_get_write_buf(BIO* bio,
659                                               uint8_t** out_write_buf,
660                                               size_t* out_buf_offset,
661                                               size_t* out_available_bytes);
662
663/* BIO_zero_copy_write_buf_done must be called after writing to a BIO using
664 * |BIO_zero_copy_get_write_buf_done| to finish the write operation. The
665 * |bytes_written| argument gives the number of bytes written.
666 *
667 * It returns one on success. In case of error it returns zero and pushes to the
668 * error stack. */
669OPENSSL_EXPORT int BIO_zero_copy_get_write_buf_done(BIO* bio,
670                                                    size_t bytes_written);
671
672
673/* BIO_NOCLOSE and |BIO_CLOSE| can be used as symbolic arguments when a "close
674 * flag" is passed to a BIO function. */
675#define BIO_NOCLOSE 0
676#define BIO_CLOSE 1
677
678/* These are passed to the BIO callback */
679#define BIO_CB_FREE 0x01
680#define BIO_CB_READ 0x02
681#define BIO_CB_WRITE 0x03
682#define BIO_CB_PUTS 0x04
683#define BIO_CB_GETS 0x05
684#define BIO_CB_CTRL 0x06
685
686/* The callback is called before and after the underling operation,
687 * The BIO_CB_RETURN flag indicates if it is after the call */
688#define BIO_CB_RETURN 0x80
689
690/* These are values of the |cmd| argument to |BIO_ctrl|. */
691#define BIO_CTRL_RESET		1  /* opt - rewind/zero etc */
692#define BIO_CTRL_EOF		2  /* opt - are we at the eof */
693#define BIO_CTRL_INFO		3  /* opt - extra tit-bits */
694#define BIO_CTRL_SET		4  /* man - set the 'IO' type */
695#define BIO_CTRL_GET		5  /* man - get the 'IO' type */
696#define BIO_CTRL_PUSH		6  /* opt - internal, used to signify change */
697#define BIO_CTRL_POP		7  /* opt - internal, used to signify change */
698#define BIO_CTRL_GET_CLOSE	8  /* man - set the 'close' on free */
699#define BIO_CTRL_SET_CLOSE	9  /* man - set the 'close' on free */
700#define BIO_CTRL_PENDING	10  /* opt - is their more data buffered */
701#define BIO_CTRL_FLUSH		11  /* opt - 'flush' buffered output */
702#define BIO_CTRL_WPENDING	13  /* opt - number of bytes still to write */
703/* callback is int cb(BIO *bio,state,ret); */
704#define BIO_CTRL_SET_CALLBACK	14  /* opt - set callback function */
705#define BIO_CTRL_GET_CALLBACK	15  /* opt - set callback function */
706#define BIO_CTRL_SET_FILENAME	30	/* BIO_s_file special */
707
708
709/* Private functions */
710
711#define BIO_FLAGS_READ 0x01
712#define BIO_FLAGS_WRITE 0x02
713#define BIO_FLAGS_IO_SPECIAL 0x04
714#define BIO_FLAGS_RWS (BIO_FLAGS_READ | BIO_FLAGS_WRITE | BIO_FLAGS_IO_SPECIAL)
715#define BIO_FLAGS_SHOULD_RETRY 0x08
716#define BIO_FLAGS_BASE64_NO_NL 0x100
717/* This is used with memory BIOs: it means we shouldn't free up or change the
718 * data in any way. */
719#define BIO_FLAGS_MEM_RDONLY 0x200
720
721/* These are the 'types' of BIOs */
722#define BIO_TYPE_NONE 0
723#define BIO_TYPE_MEM (1 | 0x0400)
724#define BIO_TYPE_FILE (2 | 0x0400)
725#define BIO_TYPE_FD (4 | 0x0400 | 0x0100)
726#define BIO_TYPE_SOCKET (5 | 0x0400 | 0x0100)
727#define BIO_TYPE_NULL (6 | 0x0400)
728#define BIO_TYPE_SSL (7 | 0x0200)
729#define BIO_TYPE_MD (8 | 0x0200)                /* passive filter */
730#define BIO_TYPE_BUFFER (9 | 0x0200)            /* filter */
731#define BIO_TYPE_CIPHER (10 | 0x0200)           /* filter */
732#define BIO_TYPE_BASE64 (11 | 0x0200)           /* filter */
733#define BIO_TYPE_CONNECT (12 | 0x0400 | 0x0100) /* socket - connect */
734#define BIO_TYPE_ACCEPT (13 | 0x0400 | 0x0100)  /* socket for accept */
735#define BIO_TYPE_PROXY_CLIENT (14 | 0x0200)     /* client proxy BIO */
736#define BIO_TYPE_PROXY_SERVER (15 | 0x0200)     /* server proxy BIO */
737#define BIO_TYPE_NBIO_TEST (16 | 0x0200)        /* server proxy BIO */
738#define BIO_TYPE_NULL_FILTER (17 | 0x0200)
739#define BIO_TYPE_BER (18 | 0x0200)        /* BER -> bin filter */
740#define BIO_TYPE_BIO (19 | 0x0400)        /* (half a) BIO pair */
741#define BIO_TYPE_LINEBUFFER (20 | 0x0200) /* filter */
742#define BIO_TYPE_DGRAM (21 | 0x0400 | 0x0100)
743#define BIO_TYPE_ASN1 (22 | 0x0200) /* filter */
744#define BIO_TYPE_COMP (23 | 0x0200) /* filter */
745
746#define BIO_TYPE_DESCRIPTOR 0x0100 /* socket, fd, connect or accept */
747#define BIO_TYPE_FILTER 0x0200
748#define BIO_TYPE_SOURCE_SINK 0x0400
749
750struct bio_method_st {
751  int type;
752  const char *name;
753  int (*bwrite)(BIO *, const char *, int);
754  int (*bread)(BIO *, char *, int);
755  /* TODO(fork): remove bputs. */
756  int (*bputs)(BIO *, const char *);
757  int (*bgets)(BIO *, char *, int);
758  long (*ctrl)(BIO *, int, long, void *);
759  int (*create)(BIO *);
760  int (*destroy)(BIO *);
761  long (*callback_ctrl)(BIO *, int, bio_info_cb);
762};
763
764struct bio_st {
765  const BIO_METHOD *method;
766  /* bio, mode, argp, argi, argl, ret */
767  long (*callback)(struct bio_st *, int, const char *, int, long, long);
768  char *cb_arg; /* first argument for the callback */
769
770  /* init is non-zero if this |BIO| has been initialised. */
771  int init;
772  /* shutdown is often used by specific |BIO_METHOD|s to determine whether
773   * they own some underlying resource. This flag can often by controlled by
774   * |BIO_set_close|. For example, whether an fd BIO closes the underlying fd
775   * when it, itself, is closed. */
776  int shutdown;
777  int flags;
778  int retry_reason;
779  /* num is a BIO-specific value. For example, in fd BIOs it's used to store a
780   * file descriptor. */
781  int num;
782  /* TODO(fork): reference counting is only used by the SSL BIO code. If we can
783   * dump that then we can remove this. We could also drop
784   * BIO_CTRL_PUSH/BIO_CTRL_POP. */
785  int references;
786  void *ptr;
787  /* next_bio points to the next |BIO| in a chain. This |BIO| owns a reference
788   * to |next_bio|. */
789  struct bio_st *next_bio; /* used by filter BIOs */
790  size_t num_read, num_write;
791
792  CRYPTO_EX_DATA ex_data;
793};
794
795#define BIO_C_SET_CONNECT			100
796#define BIO_C_DO_STATE_MACHINE			101
797#define BIO_C_SET_NBIO				102
798#define BIO_C_SET_PROXY_PARAM			103
799#define BIO_C_SET_FD				104
800#define BIO_C_GET_FD				105
801#define BIO_C_SET_FILE_PTR			106
802#define BIO_C_GET_FILE_PTR			107
803#define BIO_C_SET_FILENAME			108
804#define BIO_C_SET_SSL				109
805#define BIO_C_GET_SSL				110
806#define BIO_C_SET_MD				111
807#define BIO_C_GET_MD				112
808#define BIO_C_GET_CIPHER_STATUS			113
809#define BIO_C_SET_BUF_MEM			114
810#define BIO_C_GET_BUF_MEM_PTR			115
811#define BIO_C_GET_BUFF_NUM_LINES		116
812#define BIO_C_SET_BUFF_SIZE			117
813#define BIO_C_SET_ACCEPT			118
814#define BIO_C_SSL_MODE				119
815#define BIO_C_GET_MD_CTX			120
816#define BIO_C_GET_PROXY_PARAM			121
817#define BIO_C_SET_BUFF_READ_DATA		122 /* data to read first */
818#define BIO_C_GET_CONNECT			123
819#define BIO_C_GET_ACCEPT			124
820#define BIO_C_SET_SSL_RENEGOTIATE_BYTES		125
821#define BIO_C_GET_SSL_NUM_RENEGOTIATES		126
822#define BIO_C_SET_SSL_RENEGOTIATE_TIMEOUT	127
823#define BIO_C_FILE_SEEK				128
824#define BIO_C_GET_CIPHER_CTX			129
825#define BIO_C_SET_BUF_MEM_EOF_RETURN		130/*return end of input value*/
826#define BIO_C_SET_BIND_MODE			131
827#define BIO_C_GET_BIND_MODE			132
828#define BIO_C_FILE_TELL				133
829#define BIO_C_GET_SOCKS				134
830#define BIO_C_SET_SOCKS				135
831
832#define BIO_C_SET_WRITE_BUF_SIZE		136/* for BIO_s_bio */
833#define BIO_C_GET_WRITE_BUF_SIZE		137
834#define BIO_C_GET_WRITE_GUARANTEE		140
835#define BIO_C_GET_READ_REQUEST			141
836#define BIO_C_SHUTDOWN_WR			142
837#define BIO_C_NREAD0				143
838#define BIO_C_NREAD				144
839#define BIO_C_NWRITE0				145
840#define BIO_C_NWRITE				146
841#define BIO_C_RESET_READ_REQUEST		147
842#define BIO_C_SET_MD_CTX			148
843
844#define BIO_C_SET_PREFIX			149
845#define BIO_C_GET_PREFIX			150
846#define BIO_C_SET_SUFFIX			151
847#define BIO_C_GET_SUFFIX			152
848
849#define BIO_C_SET_EX_ARG			153
850#define BIO_C_GET_EX_ARG			154
851
852
853#if defined(__cplusplus)
854}  /* extern C */
855#endif
856
857#define BIO_F_bio_make_pair 100
858#define BIO_F_bio_ctrl 101
859#define BIO_F_buffer_ctrl 102
860#define BIO_F_BIO_new_file 103
861#define BIO_F_file_read 104
862#define BIO_F_BIO_new 105
863#define BIO_F_bio_io 106
864#define BIO_F_BIO_new_mem_buf 107
865#define BIO_F_mem_write 108
866#define BIO_F_conn_state 109
867#define BIO_F_conn_ctrl 110
868#define BIO_F_file_ctrl 111
869#define BIO_F_BIO_callback_ctrl 112
870#define BIO_F_bio_ip_and_port_to_socket_and_addr 113
871#define BIO_F_bio_write 114
872#define BIO_F_BIO_ctrl 115
873#define BIO_F_BIO_zero_copy_get_write_buf 116
874#define BIO_F_BIO_zero_copy_get_write_buf_done 117
875#define BIO_F_BIO_zero_copy_get_read_buf 118
876#define BIO_F_BIO_zero_copy_get_read_buf_done 119
877#define BIO_R_UNSUPPORTED_METHOD 100
878#define BIO_R_NO_PORT_SPECIFIED 101
879#define BIO_R_NO_HOSTNAME_SPECIFIED 102
880#define BIO_R_IN_USE 103
881#define BIO_R_UNINITIALIZED 104
882#define BIO_R_CONNECT_ERROR 105
883#define BIO_R_KEEPALIVE 106
884#define BIO_R_BROKEN_PIPE 107
885#define BIO_R_NBIO_CONNECT_ERROR 108
886#define BIO_R_BAD_FOPEN_MODE 109
887#define BIO_R_ASN1_OBJECT_TOO_LONG 110
888#define BIO_R_INVALID_ARGUMENT 111
889#define BIO_R_WRITE_TO_READ_ONLY_BIO 112
890#define BIO_R_ERROR_SETTING_NBIO 113
891#define BIO_R_SYS_LIB 114
892#define BIO_R_NO_SUCH_FILE 115
893#define BIO_R_NULL_PARAMETER 116
894#define BIO_R_UNABLE_TO_CREATE_SOCKET 117
895
896#endif  /* OPENSSL_HEADER_BIO_H */
897