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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 <stdio.h>  /* For FILE */
63 
64 #include <openssl/err.h> /* for ERR_print_errors_fp */
65 #include <openssl/ex_data.h>
66 #include <openssl/stack.h>
67 #include <openssl/thread.h>
68 
69 #if defined(__cplusplus)
70 extern "C" {
71 #endif
72 
73 
74 /* BIO abstracts over a file-descriptor like interface. */
75 
76 
77 /* Allocation and freeing. */
78 
79 DEFINE_STACK_OF(BIO);
80 
81 /* BIO_new creates a new BIO with the given type and a reference count of one.
82  * It returns the fresh |BIO|, or NULL on error. */
83 OPENSSL_EXPORT BIO *BIO_new(const BIO_METHOD *type);
84 
85 /* BIO_free decrements the reference count of |bio|. If the reference count
86  * drops to zero, it (optionally) calls the BIO's callback with |BIO_CB_FREE|,
87  * frees the ex_data and then, if the BIO has a destroy callback for the
88  * method, calls it. Finally it frees |bio| itself. It then repeats that for
89  * the next BIO in the chain, if any.
90  *
91  * It returns one on success or zero otherwise. */
92 OPENSSL_EXPORT int BIO_free(BIO *bio);
93 
94 /* BIO_vfree performs the same actions as |BIO_free|, but has a void return
95  * value. This is provided for API-compat.
96  *
97  * TODO(fork): remove. */
98 OPENSSL_EXPORT void BIO_vfree(BIO *bio);
99 
100 /* BIO_up_ref increments the reference count of |bio| and returns it. */
101 OPENSSL_EXPORT BIO *BIO_up_ref(BIO *bio);
102 
103 
104 /* Basic I/O. */
105 
106 /* BIO_read attempts to read |len| bytes into |data|. It returns the number of
107  * bytes read, zero on EOF, or a negative number on error. */
108 OPENSSL_EXPORT int BIO_read(BIO *bio, void *data, int len);
109 
110 /* BIO_gets "reads a line" from |bio| and puts at most |size| bytes into |buf|.
111  * It returns the number of bytes read or a negative number on error. The
112  * phrase "reads a line" is in quotes in the previous sentence because the
113  * exact operation depends on the BIO's method. For example, a digest BIO will
114  * return the digest in response to a |BIO_gets| call.
115  *
116  * TODO(fork): audit the set of BIOs that we end up needing. If all actually
117  * return a line for this call, remove the warning above. */
118 OPENSSL_EXPORT int BIO_gets(BIO *bio, char *buf, int size);
119 
120 /* BIO_write writes |len| bytes from |data| to BIO. It returns the number of
121  * bytes written or a negative number on error. */
122 OPENSSL_EXPORT int BIO_write(BIO *bio, const void *data, int len);
123 
124 /* BIO_puts writes a NUL terminated string from |buf| to |bio|. It returns the
125  * number of bytes written or a negative number on error. */
126 OPENSSL_EXPORT int BIO_puts(BIO *bio, const char *buf);
127 
128 /* BIO_flush flushes any buffered output. It returns one on success and zero
129  * otherwise. */
130 OPENSSL_EXPORT int BIO_flush(BIO *bio);
131 
132 
133 /* Low-level control functions.
134  *
135  * These are generic functions for sending control requests to a BIO. In
136  * general one should use the wrapper functions like |BIO_get_close|. */
137 
138 /* BIO_ctrl sends the control request |cmd| to |bio|. The |cmd| argument should
139  * be one of the |BIO_C_*| values. */
140 OPENSSL_EXPORT long BIO_ctrl(BIO *bio, int cmd, long larg, void *parg);
141 
142 /* BIO_ptr_ctrl acts like |BIO_ctrl| but passes the address of a |void*|
143  * pointer as |parg| and returns the value that is written to it, or NULL if
144  * the control request returns <= 0. */
145 OPENSSL_EXPORT char *BIO_ptr_ctrl(BIO *bp, int cmd, long larg);
146 
147 /* BIO_int_ctrl acts like |BIO_ctrl| but passes the address of a copy of |iarg|
148  * as |parg|. */
149 OPENSSL_EXPORT long BIO_int_ctrl(BIO *bp, int cmd, long larg, int iarg);
150 
151 /* BIO_reset resets |bio| to its initial state, the precise meaning of which
152  * depends on the concrete type of |bio|. It returns one on success and zero
153  * otherwise. */
154 OPENSSL_EXPORT int BIO_reset(BIO *bio);
155 
156 /* BIO_set_flags ORs |flags| with |bio->flags|. */
157 OPENSSL_EXPORT void BIO_set_flags(BIO *bio, int flags);
158 
159 /* BIO_test_flags returns |bio->flags| AND |flags|. */
160 OPENSSL_EXPORT int BIO_test_flags(const BIO *bio, int flags);
161 
162 /* BIO_should_read returns non-zero if |bio| encountered a temporary error
163  * while reading (i.e. EAGAIN), indicating that the caller should retry the
164  * read. */
165 OPENSSL_EXPORT int BIO_should_read(const BIO *bio);
166 
167 /* BIO_should_write returns non-zero if |bio| encountered a temporary error
168  * while writing (i.e. EAGAIN), indicating that the caller should retry the
169  * write. */
170 OPENSSL_EXPORT int BIO_should_write(const BIO *bio);
171 
172 /* BIO_should_retry returns non-zero if the reason that caused a failed I/O
173  * operation is temporary and thus the operation should be retried. Otherwise,
174  * it was a permanent error and it returns zero. */
175 OPENSSL_EXPORT int BIO_should_retry(const BIO *bio);
176 
177 /* BIO_should_io_special returns non-zero if |bio| encountered a temporary
178  * error while performing a special I/O operation, indicating that the caller
179  * should retry. The operation that caused the error is returned by
180  * |BIO_get_retry_reason|. */
181 OPENSSL_EXPORT int BIO_should_io_special(const BIO *bio);
182 
183 /* BIO_RR_SSL_X509_LOOKUP indicates that an SSL BIO blocked because the SSL
184  * library returned with SSL_ERROR_WANT_X509_LOOKUP.
185  *
186  * TODO(fork): remove. */
187 #define BIO_RR_SSL_X509_LOOKUP 0x01
188 
189 /* BIO_RR_CONNECT indicates that a connect would have blocked */
190 #define BIO_RR_CONNECT 0x02
191 
192 /* BIO_RR_ACCEPT indicates that an accept would have blocked */
193 #define BIO_RR_ACCEPT 0x03
194 
195 /* BIO_RR_SSL_CHANNEL_ID_LOOKUP indicates that the ChannelID code cannot find
196  * a private key for a TLS connection. */
197 #define BIO_RR_SSL_CHANNEL_ID_LOOKUP 0x04
198 
199 /* BIO_get_retry_reason returns the special I/O operation that needs to be
200  * retried. The return value is one of the |BIO_RR_*| values. */
201 OPENSSL_EXPORT int BIO_get_retry_reason(const BIO *bio);
202 
203 /* BIO_clear_flags ANDs |bio->flags| with the bitwise-complement of |flags|. */
204 OPENSSL_EXPORT void BIO_clear_flags(BIO *bio, int flags);
205 
206 /* BIO_set_retry_read sets the |BIO_FLAGS_READ| and |BIO_FLAGS_SHOULD_RETRY|
207  * flags on |bio|. */
208 OPENSSL_EXPORT void BIO_set_retry_read(BIO *bio);
209 
210 /* BIO_set_retry_read sets the |BIO_FLAGS_WRITE| and |BIO_FLAGS_SHOULD_RETRY|
211  * flags on |bio|. */
212 OPENSSL_EXPORT void BIO_set_retry_write(BIO *bio);
213 
214 /* BIO_get_retry_flags gets the |BIO_FLAGS_READ|, |BIO_FLAGS_WRITE|,
215  * |BIO_FLAGS_IO_SPECIAL| and |BIO_FLAGS_SHOULD_RETRY| flags from |bio|. */
216 OPENSSL_EXPORT int BIO_get_retry_flags(BIO *bio);
217 
218 /* BIO_clear_retry_flags clears the |BIO_FLAGS_READ|, |BIO_FLAGS_WRITE|,
219  * |BIO_FLAGS_IO_SPECIAL| and |BIO_FLAGS_SHOULD_RETRY| flags from |bio|. */
220 OPENSSL_EXPORT void BIO_clear_retry_flags(BIO *bio);
221 
222 /* BIO_method_type returns the type of |bio|, which is one of the |BIO_TYPE_*|
223  * values. */
224 OPENSSL_EXPORT int BIO_method_type(const BIO *bio);
225 
226 /* bio_info_cb is the type of a callback function that can be called for most
227  * BIO operations. The |event| argument is one of |BIO_CB_*| and can be ORed
228  * with |BIO_CB_RETURN| if the callback is being made after the operation in
229  * question. In that case, |return_value| will contain the return value from
230  * the operation. */
231 typedef long (*bio_info_cb)(BIO *bio, int event, const char *parg, int cmd,
232                             long larg, long return_value);
233 
234 /* BIO_callback_ctrl allows the callback function to be manipulated. The |cmd|
235  * arg will generally be |BIO_CTRL_SET_CALLBACK| but arbitary command values
236  * can be interpreted by the |BIO|. */
237 OPENSSL_EXPORT long BIO_callback_ctrl(BIO *bio, int cmd, bio_info_cb fp);
238 
239 /* BIO_pending returns the number of bytes pending to be read. */
240 OPENSSL_EXPORT size_t BIO_pending(const BIO *bio);
241 
242 /* BIO_ctrl_pending calls |BIO_pending| and exists only for compatibility with
243  * OpenSSL. */
244 OPENSSL_EXPORT size_t BIO_ctrl_pending(const BIO *bio);
245 
246 /* BIO_wpending returns the number of bytes pending to be written. */
247 OPENSSL_EXPORT size_t BIO_wpending(const BIO *bio);
248 
249 /* BIO_set_close sets the close flag for |bio|. The meaning of which depends on
250  * the type of |bio| but, for example, a memory BIO interprets the close flag
251  * as meaning that it owns its buffer. It returns one on success and zero
252  * otherwise. */
253 OPENSSL_EXPORT int BIO_set_close(BIO *bio, int close_flag);
254 
255 /* BIO_set_callback sets a callback function that will be called before and
256  * after most operations. See the comment above |bio_info_cb|. */
257 OPENSSL_EXPORT void BIO_set_callback(BIO *bio, bio_info_cb callback_func);
258 
259 /* BIO_set_callback_arg sets the opaque pointer value that can be read within a
260  * callback with |BIO_get_callback_arg|. */
261 OPENSSL_EXPORT void BIO_set_callback_arg(BIO *bio, char *arg);
262 
263 /* BIO_get_callback_arg returns the last value of the opaque callback pointer
264  * set by |BIO_set_callback_arg|. */
265 OPENSSL_EXPORT char *BIO_get_callback_arg(const BIO *bio);
266 
267 /* BIO_number_read returns the number of bytes that have been read from
268  * |bio|. */
269 OPENSSL_EXPORT size_t BIO_number_read(const BIO *bio);
270 
271 /* BIO_number_written returns the number of bytes that have been written to
272  * |bio|. */
273 OPENSSL_EXPORT size_t BIO_number_written(const BIO *bio);
274 
275 
276 /* Managing chains of BIOs.
277  *
278  * BIOs can be put into chains where the output of one is used as the input of
279  * the next etc. The most common case is a buffering BIO, which accepts and
280  * buffers writes until flushed into the next BIO in the chain. */
281 
282 /* BIO_push adds |appended_bio| to the end of the chain with |bio| at the head.
283  * It returns |bio|. Note that |appended_bio| may be the head of a chain itself
284  * and thus this function can be used to join two chains.
285  *
286  * BIO_push takes ownership of the caller's reference to |appended_bio|. */
287 OPENSSL_EXPORT BIO *BIO_push(BIO *bio, BIO *appended_bio);
288 
289 /* BIO_pop removes |bio| from the head of a chain and returns the next BIO in
290  * the chain, or NULL if there is no next BIO.
291  *
292  * The caller takes ownership of the chain's reference to |bio|. */
293 OPENSSL_EXPORT BIO *BIO_pop(BIO *bio);
294 
295 /* BIO_next returns the next BIO in the chain after |bio|, or NULL if there is
296  * no such BIO. */
297 OPENSSL_EXPORT BIO *BIO_next(BIO *bio);
298 
299 /* BIO_free_all calls |BIO_free|.
300  *
301  * TODO(fork): update callers and remove. */
302 OPENSSL_EXPORT void BIO_free_all(BIO *bio);
303 
304 /* BIO_find_type walks a chain of BIOs and returns the first that matches
305  * |type|, which is one of the |BIO_TYPE_*| values. */
306 OPENSSL_EXPORT BIO *BIO_find_type(BIO *bio, int type);
307 
308 /* BIO_copy_next_retry sets the retry flags and |retry_reason| of |bio| from
309  * the next BIO in the chain. */
310 OPENSSL_EXPORT void BIO_copy_next_retry(BIO *bio);
311 
312 
313 /* Printf functions.
314  *
315  * These functions are versions of printf functions that output to a BIO rather
316  * than a FILE. */
317 #ifdef __GNUC__
318 #define __bio_h__attr__ __attribute__
319 #else
320 #define __bio_h__attr__(x)
321 #endif
322 OPENSSL_EXPORT int BIO_printf(BIO *bio, const char *format, ...)
323     __bio_h__attr__((__format__(__printf__, 2, 3)));
324 #undef __bio_h__attr__
325 
326 
327 /* Utility functions. */
328 
329 /* BIO_indent prints min(|indent|, |max_indent|) spaces. It returns one on
330  * success and zero otherwise. */
331 OPENSSL_EXPORT int BIO_indent(BIO *bio, unsigned indent, unsigned max_indent);
332 
333 /* BIO_hexdump writes a hex dump of |data| to |bio|. Each line will be indented
334  * by |indent| spaces. */
335 OPENSSL_EXPORT int BIO_hexdump(BIO *bio, const uint8_t *data, size_t len,
336                                unsigned indent);
337 
338 /* BIO_print_errors prints the current contents of the error stack to |bio|
339  * using human readable strings where possible. */
340 OPENSSL_EXPORT void BIO_print_errors(BIO *bio);
341 
342 /* BIO_read_asn1 reads a single ASN.1 object from |bio|. If successful it sets
343  * |*out| to be an allocated buffer (that should be freed with |OPENSSL_free|),
344  * |*out_size| to the length, in bytes, of that buffer and returns one.
345  * Otherwise it returns zero.
346  *
347  * If the length of the object is greater than |max_len| or 2^32 then the
348  * function will fail. Long-form tags are not supported. If the length of the
349  * object is indefinite the full contents of |bio| are read, unless it would be
350  * greater than |max_len|, in which case the function fails.
351  *
352  * If the function fails then some unknown amount of data may have been read
353  * from |bio|. */
354 OPENSSL_EXPORT int BIO_read_asn1(BIO *bio, uint8_t **out, size_t *out_len,
355                                  size_t max_len);
356 
357 
358 /* Memory BIOs.
359  *
360  * Memory BIOs can be used as a read-only source (with |BIO_new_mem_buf|) or a
361  * writable sink (with |BIO_new|, |BIO_s_mem| and |BIO_get_mem_buf|). Data
362  * written to a writable, memory BIO can be recalled by reading from it.
363  *
364  * Calling |BIO_reset| on a read-only BIO resets it to the original contents.
365  * On a writable BIO, it clears any data.
366  *
367  * If the close flag is set to |BIO_NOCLOSE| (not the default) then the
368  * underlying |BUF_MEM| will not be freed when the |BIO| is freed.
369  *
370  * Memory BIOs support |BIO_gets| and |BIO_puts|.
371  *
372  * |BIO_eof| is true if no data is in the BIO.
373  *
374  * |BIO_ctrl_pending| returns the number of bytes currently stored. */
375 
376 /* BIO_s_mem returns a |BIO_METHOD| that uses a in-memory buffer. */
377 OPENSSL_EXPORT const BIO_METHOD *BIO_s_mem(void);
378 
379 /* BIO_new_mem_buf creates BIO that reads and writes from |len| bytes at |buf|.
380  * It does not take ownership of |buf|. It returns the BIO or NULL on error.
381  *
382  * If |len| is negative, then |buf| is treated as a NUL-terminated string, but
383  * don't depend on this in new code. */
384 OPENSSL_EXPORT BIO *BIO_new_mem_buf(void *buf, int len);
385 
386 /* BIO_mem_contents sets |*out_contents| to point to the current contents of
387  * |bio| and |*out_len| to contain the length of that data. It returns one on
388  * success and zero otherwise. */
389 OPENSSL_EXPORT int BIO_mem_contents(const BIO *bio,
390                                     const uint8_t **out_contents,
391                                     size_t *out_len);
392 
393 /* BIO_get_mem_data sets |*contents| to point to the current contents of |bio|
394  * and returns the length of the data.
395  *
396  * WARNING: don't use this, use |BIO_mem_contents|. A return value of zero from
397  * this function can mean either that it failed or that the memory buffer is
398  * empty. */
399 OPENSSL_EXPORT long BIO_get_mem_data(BIO *bio, char **contents);
400 
401 /* BIO_get_mem_ptr sets |*out| to a BUF_MEM containing the current contents of
402  * |bio|. It returns one on success or zero on error. */
403 OPENSSL_EXPORT int BIO_get_mem_ptr(BIO *bio, BUF_MEM **out);
404 
405 /* BIO_set_mem_buf sets |b| as the contents of |bio|. If |take_ownership| is
406  * non-zero, then |b| will be freed when |bio| is closed. Returns one on
407  * success or zero otherwise. */
408 OPENSSL_EXPORT int BIO_set_mem_buf(BIO *bio, BUF_MEM *b, int take_ownership);
409 
410 /* BIO_set_mem_eof_return sets the value that will be returned from reading
411  * |bio| when empty. If |eof_value| is zero then an empty memory BIO will
412  * return EOF (that is it will return zero and |BIO_should_retry| will be
413  * false). If |eof_value| is non zero then it will return |eof_value| when it
414  * is empty and it will set the read retry flag (that is |BIO_read_retry| is
415  * true). To avoid ambiguity with a normal positive return value, |eof_value|
416  * should be set to a negative value, typically -1.
417  *
418  * For a read-only BIO, the default is zero (EOF). For a writable BIO, the
419  * default is -1 so that additional data can be written once exhausted. */
420 OPENSSL_EXPORT int BIO_set_mem_eof_return(BIO *bio, int eof_value);
421 
422 
423 /* File descriptor BIOs.
424  *
425  * File descriptor BIOs are wrappers around the system's |read| and |write|
426  * functions. If the close flag is set then then |close| is called on the
427  * underlying file descriptor when the BIO is freed.
428  *
429  * |BIO_reset| attempts to seek the file pointer to the start of file using
430  * |lseek|.
431  *
432  * |BIO_seek| sets the file pointer to position |off| from start of file using
433  * |lseek|.
434  *
435  * |BIO_tell| returns the current file position. */
436 
437 /* BIO_s_fd returns a |BIO_METHOD| for file descriptor fds. */
438 OPENSSL_EXPORT const BIO_METHOD *BIO_s_fd(void);
439 
440 /* BIO_new_fd creates a new file descriptor BIO wrapping |fd|. If |close_flag|
441  * is non-zero, then |fd| will be closed when the BIO is. */
442 OPENSSL_EXPORT BIO *BIO_new_fd(int fd, int close_flag);
443 
444 /* BIO_set_fd sets the file descriptor of |bio| to |fd|. If |close_flag| is
445  * non-zero then |fd| will be closed when |bio| is. It returns one on success
446  * or zero on error. */
447 OPENSSL_EXPORT int BIO_set_fd(BIO *bio, int fd, int close_flag);
448 
449 /* BIO_get_fd sets |*out_fd| to the file descriptor currently in use by |bio|.
450  * It returns one on success and zero on error. */
451 OPENSSL_EXPORT int BIO_get_fd(BIO *bio, int *out_fd);
452 
453 
454 /* File BIOs.
455  *
456  * File BIOs are wrappers around a C |FILE| object.
457  *
458  * |BIO_flush| on a file BIO calls |fflush| on the wrapped stream.
459  *
460  * |BIO_reset| attempts to seek the file pointer to the start of file using
461  * |fseek|.
462  *
463  * |BIO_seek| sets the file pointer to the given position from the start of
464  * file using |fseek|.
465  *
466  * |BIO_eof| calls |feof|.
467  *
468  * Setting the close flag causes |fclose| to be called on the stream when the
469  * BIO is freed. */
470 
471 /* BIO_s_file returns a BIO_METHOD that wraps a |FILE|. */
472 OPENSSL_EXPORT const BIO_METHOD *BIO_s_file(void);
473 
474 /* BIO_new_file creates a file BIO by opening |filename| with the given mode.
475  * See the |fopen| manual page for details of the mode argument. */
476 OPENSSL_EXPORT BIO *BIO_new_file(const char *filename, const char *mode);
477 
478 /* BIO_new_fp creates a new file BIO that wraps the given |FILE|. If
479  * |close_flag| is |BIO_CLOSE|, then |fclose| will be called on |stream| when
480  * the BIO is closed. */
481 OPENSSL_EXPORT BIO *BIO_new_fp(FILE *stream, int close_flag);
482 
483 /* BIO_get_fp sets |*out_file| to the current |FILE| for |bio|. It returns one
484  * on success and zero otherwise. */
485 OPENSSL_EXPORT int BIO_get_fp(BIO *bio, FILE **out_file);
486 
487 /* BIO_set_fp sets the |FILE| for |bio|. If |close_flag| is |BIO_CLOSE| then
488  * |fclose| will be called on |file| when |bio| is closed. It returns one on
489  * sucess and zero otherwise. */
490 OPENSSL_EXPORT int BIO_set_fp(BIO *bio, FILE *file, int close_flag);
491 
492 /* BIO_read_filename opens |filename| for reading and sets the result as the
493  * |FILE| for |bio|. It returns one on success and zero otherwise. The |FILE|
494  * will be closed when |bio| is freed. */
495 OPENSSL_EXPORT int BIO_read_filename(BIO *bio, const char *filename);
496 
497 /* BIO_write_filename opens |filename| for writing and sets the result as the
498  * |FILE| for |bio|. It returns one on success and zero otherwise. The |FILE|
499  * will be closed when |bio| is freed. */
500 OPENSSL_EXPORT int BIO_write_filename(BIO *bio, const char *filename);
501 
502 /* BIO_append_filename opens |filename| for appending and sets the result as
503  * the |FILE| for |bio|. It returns one on success and zero otherwise. The
504  * |FILE| will be closed when |bio| is freed. */
505 OPENSSL_EXPORT int BIO_append_filename(BIO *bio, const char *filename);
506 
507 /* BIO_rw_filename opens |filename| for reading and writing and sets the result
508  * as the |FILE| for |bio|. It returns one on success and zero otherwise. The
509  * |FILE| will be closed when |bio| is freed. */
510 OPENSSL_EXPORT int BIO_rw_filename(BIO *bio, const char *filename);
511 
512 
513 /* Buffer BIOs.
514  *
515  * Buffer BIOs are a filter-type BIO, i.e. they are designed to be used in a
516  * chain of BIOs. They provide buffering to reduce the number of operations on
517  * the underlying BIOs. */
518 
519 OPENSSL_EXPORT const BIO_METHOD *BIO_f_buffer(void);
520 
521 /* BIO_set_read_buffer_size sets the size, in bytes, of the read buffer and
522  * clears it. It returns one on success and zero on failure. */
523 OPENSSL_EXPORT int BIO_set_read_buffer_size(BIO *bio, int buffer_size);
524 
525 /* BIO_set_write_buffer_size sets the size, in bytes, of the write buffer and
526  * clears it. It returns one on success and zero on failure. */
527 OPENSSL_EXPORT int BIO_set_write_buffer_size(BIO *bio, int buffer_size);
528 
529 
530 /* Socket BIOs. */
531 
532 OPENSSL_EXPORT const BIO_METHOD *BIO_s_socket(void);
533 
534 /* BIO_new_socket allocates and initialises a fresh BIO which will read and
535  * write to the socket |fd|. If |close_flag| is |BIO_CLOSE| then closing the
536  * BIO will close |fd|. It returns the fresh |BIO| or NULL on error. */
537 OPENSSL_EXPORT BIO *BIO_new_socket(int fd, int close_flag);
538 
539 
540 /* Connect BIOs.
541  *
542  * A connection BIO creates a network connection and transfers data over the
543  * resulting socket. */
544 
545 OPENSSL_EXPORT const BIO_METHOD *BIO_s_connect(void);
546 
547 /* BIO_new_connect returns a BIO that connects to the given hostname and port.
548  * The |host_and_optional_port| argument should be of the form
549  * "www.example.com" or "www.example.com:443". If the port is omitted, it must
550  * be provided with |BIO_set_conn_port|.
551  *
552  * It returns the new BIO on success, or NULL on error. */
553 OPENSSL_EXPORT BIO *BIO_new_connect(const char *host_and_optional_port);
554 
555 /* BIO_set_conn_hostname sets |host_and_optional_port| as the hostname and
556  * optional port that |bio| will connect to. If the port is omitted, it must be
557  * provided with |BIO_set_conn_port|.
558  *
559  * It returns one on success and zero otherwise. */
560 OPENSSL_EXPORT int BIO_set_conn_hostname(BIO *bio,
561                                          const char *host_and_optional_port);
562 
563 /* BIO_set_conn_port sets |port_str| as the port or service name that |bio|
564  * will connect to. It returns one on success and zero otherwise. */
565 OPENSSL_EXPORT int BIO_set_conn_port(BIO *bio, const char *port_str);
566 
567 /* BIO_set_nbio sets whether |bio| will use non-blocking I/O operations. It
568  * returns one on success and zero otherwise. */
569 OPENSSL_EXPORT int BIO_set_nbio(BIO *bio, int on);
570 
571 
572 /* Datagram BIOs.
573  *
574  * TODO(fork): not implemented. */
575 
576 #define BIO_CTRL_DGRAM_QUERY_MTU 40 /* as kernel for current MTU */
577 
578 #define BIO_CTRL_DGRAM_SET_MTU 42 /* set cached value for  MTU. want to use
579                                      this if asking the kernel fails */
580 
581 #define BIO_CTRL_DGRAM_MTU_EXCEEDED 43 /* check whether the MTU was exceed in
582                                           the previous write operation. */
583 
584 #define BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT \
585   45 /* Next DTLS handshake timeout to adjust socket timeouts */
586 
587 #define BIO_CTRL_DGRAM_GET_PEER           46
588 
589 #define BIO_CTRL_DGRAM_GET_FALLBACK_MTU   47
590 
591 
592 /* BIO Pairs.
593  *
594  * BIO pairs provide a "loopback" like system: a pair of BIOs where data
595  * written to one can be read from the other and vice versa. */
596 
597 /* BIO_new_bio_pair sets |*out1| and |*out2| to two freshly created BIOs where
598  * data written to one can be read from the other and vice versa. The
599  * |writebuf1| argument gives the size of the buffer used in |*out1| and
600  * |writebuf2| for |*out2|. It returns one on success and zero on error. */
601 OPENSSL_EXPORT int BIO_new_bio_pair(BIO **out1, size_t writebuf1, BIO **out2,
602                                     size_t writebuf2);
603 
604 /* BIO_new_bio_pair_external_buf is the same as |BIO_new_bio_pair| with the
605  * difference that the caller keeps ownership of the write buffers
606  * |ext_writebuf1_len| and |ext_writebuf2_len|. This is useful when using zero
607  * copy API for read and write operations, in cases where the buffers need to
608  * outlive the BIO pairs. It returns one on success and zero on error. */
609 OPENSSL_EXPORT int BIO_new_bio_pair_external_buf(BIO** bio1_p,
610                                                  size_t writebuf1_len,
611                                                  uint8_t* ext_writebuf1,
612                                                  BIO** bio2_p,
613                                                  size_t writebuf2_len,
614                                                  uint8_t* ext_writebuf2);
615 
616 /* BIO_ctrl_get_read_request returns the number of bytes that the other side of
617  * |bio| tried (unsuccessfully) to read. */
618 OPENSSL_EXPORT size_t BIO_ctrl_get_read_request(BIO *bio);
619 
620 /* BIO_ctrl_get_write_guarantee returns the number of bytes that |bio| (which
621  * must have been returned by |BIO_new_bio_pair|) will accept on the next
622  * |BIO_write| call. */
623 OPENSSL_EXPORT size_t BIO_ctrl_get_write_guarantee(BIO *bio);
624 
625 /* BIO_shutdown_wr marks |bio| as closed, from the point of view of the other
626  * side of the pair. Future |BIO_write| calls on |bio| will fail. It returns
627  * one on success and zero otherwise. */
628 OPENSSL_EXPORT int BIO_shutdown_wr(BIO *bio);
629 
630 
631 /* Zero copy versions of BIO_read and BIO_write for BIO pairs. */
632 
633 /* BIO_zero_copy_get_read_buf initiates a zero copy read operation.
634  * |out_read_buf| is set to the internal read buffer, and |out_buf_offset| is
635  * set to the current read position of |out_read_buf|. The number of bytes
636  * available for read from |out_read_buf| + |out_buf_offset| is returned in
637  * |out_available_bytes|. Note that this function might report fewer bytes
638  * available than |BIO_pending|, if the internal ring buffer is wrapped. It
639  * returns one on success. In case of error it returns zero and pushes to the
640  * error stack.
641  *
642  * The zero copy read operation is completed by calling
643  * |BIO_zero_copy_get_read_buf_done|. Neither |BIO_zero_copy_get_read_buf| nor
644  * any other I/O read operation may be called while a zero copy read operation
645  * is active. */
646 OPENSSL_EXPORT int BIO_zero_copy_get_read_buf(BIO* bio,
647                                               uint8_t** out_read_buf,
648                                               size_t* out_buf_offset,
649                                               size_t* out_available_bytes);
650 
651 /* BIO_zero_copy_get_read_buf_done must be called after reading from a BIO using
652  * |BIO_zero_copy_get_read_buf| to finish the read operation. The |bytes_read|
653  * argument is the number of bytes read.
654  *
655  * It returns one on success. In case of error it returns zero and pushes to the
656  * error stack. */
657 OPENSSL_EXPORT int BIO_zero_copy_get_read_buf_done(BIO* bio, size_t bytes_read);
658 
659 /* BIO_zero_copy_get_write_buf_done initiates a zero copy write operation.
660  * |out_write_buf| is set to to the internal write buffer, and |out_buf_offset|
661  * is set to the current write position of |out_write_buf|.
662  * The number of bytes available for write from |out_write_buf| +
663  * |out_buf_offset| is returned in |out_available_bytes|. Note that this
664  * function might report fewer bytes available than
665  * |BIO_ctrl_get_write_guarantee|, if the internal buffer is wrapped. It returns
666  * one on success. In case of error it returns zero and pushes to the error
667  * stack.
668  *
669  * The zero copy write operation is completed by calling
670  * |BIO_zero_copy_write_buf_done|. Neither |BIO_zero_copy_get_write_buf|
671  * nor any other I/O write operation may be called while a zero copy write
672  * operation is active. */
673 OPENSSL_EXPORT int BIO_zero_copy_get_write_buf(BIO* bio,
674                                                uint8_t** out_write_buf,
675                                                size_t* out_buf_offset,
676                                                size_t* out_available_bytes);
677 
678 /* BIO_zero_copy_write_buf_done must be called after writing to a BIO using
679  * |BIO_zero_copy_get_write_buf_done| to finish the write operation. The
680  * |bytes_written| argument gives the number of bytes written.
681  *
682  * It returns one on success. In case of error it returns zero and pushes to the
683  * error stack. */
684 OPENSSL_EXPORT int BIO_zero_copy_get_write_buf_done(BIO* bio,
685                                                     size_t bytes_written);
686 
687 
688 /* BIO_NOCLOSE and |BIO_CLOSE| can be used as symbolic arguments when a "close
689  * flag" is passed to a BIO function. */
690 #define BIO_NOCLOSE 0
691 #define BIO_CLOSE 1
692 
693 /* These are passed to the BIO callback */
694 #define BIO_CB_FREE 0x01
695 #define BIO_CB_READ 0x02
696 #define BIO_CB_WRITE 0x03
697 #define BIO_CB_PUTS 0x04
698 #define BIO_CB_GETS 0x05
699 #define BIO_CB_CTRL 0x06
700 
701 /* The callback is called before and after the underling operation,
702  * The BIO_CB_RETURN flag indicates if it is after the call */
703 #define BIO_CB_RETURN 0x80
704 
705 /* These are values of the |cmd| argument to |BIO_ctrl|. */
706 #define BIO_CTRL_RESET		1  /* opt - rewind/zero etc */
707 #define BIO_CTRL_EOF		2  /* opt - are we at the eof */
708 #define BIO_CTRL_INFO		3  /* opt - extra tit-bits */
709 #define BIO_CTRL_SET		4  /* man - set the 'IO' type */
710 #define BIO_CTRL_GET		5  /* man - get the 'IO' type */
711 #define BIO_CTRL_GET_CLOSE	8  /* man - set the 'close' on free */
712 #define BIO_CTRL_SET_CLOSE	9  /* man - set the 'close' on free */
713 #define BIO_CTRL_PENDING	10  /* opt - is their more data buffered */
714 #define BIO_CTRL_FLUSH		11  /* opt - 'flush' buffered output */
715 #define BIO_CTRL_WPENDING	13  /* opt - number of bytes still to write */
716 /* callback is int cb(BIO *bio,state,ret); */
717 #define BIO_CTRL_SET_CALLBACK	14  /* opt - set callback function */
718 #define BIO_CTRL_GET_CALLBACK	15  /* opt - set callback function */
719 #define BIO_CTRL_SET_FILENAME	30	/* BIO_s_file special */
720 
721 
722 /* Android compatibility section.
723  *
724  * A previous version of BoringSSL used in Android renamed ERR_print_errors_fp
725  * to BIO_print_errors_fp. It has subsequently been renamed back to
726  * ERR_print_errors_fp. */
727 #define BIO_print_errors_fp ERR_print_errors_fp
728 
729 
730 /* Private functions */
731 
732 #define BIO_FLAGS_READ 0x01
733 #define BIO_FLAGS_WRITE 0x02
734 #define BIO_FLAGS_IO_SPECIAL 0x04
735 #define BIO_FLAGS_RWS (BIO_FLAGS_READ | BIO_FLAGS_WRITE | BIO_FLAGS_IO_SPECIAL)
736 #define BIO_FLAGS_SHOULD_RETRY 0x08
737 #define BIO_FLAGS_BASE64_NO_NL 0x100
738 /* This is used with memory BIOs: it means we shouldn't free up or change the
739  * data in any way. */
740 #define BIO_FLAGS_MEM_RDONLY 0x200
741 
742 /* These are the 'types' of BIOs */
743 #define BIO_TYPE_NONE 0
744 #define BIO_TYPE_MEM (1 | 0x0400)
745 #define BIO_TYPE_FILE (2 | 0x0400)
746 #define BIO_TYPE_FD (4 | 0x0400 | 0x0100)
747 #define BIO_TYPE_SOCKET (5 | 0x0400 | 0x0100)
748 #define BIO_TYPE_NULL (6 | 0x0400)
749 #define BIO_TYPE_SSL (7 | 0x0200)
750 #define BIO_TYPE_MD (8 | 0x0200)                /* passive filter */
751 #define BIO_TYPE_BUFFER (9 | 0x0200)            /* filter */
752 #define BIO_TYPE_CIPHER (10 | 0x0200)           /* filter */
753 #define BIO_TYPE_BASE64 (11 | 0x0200)           /* filter */
754 #define BIO_TYPE_CONNECT (12 | 0x0400 | 0x0100) /* socket - connect */
755 #define BIO_TYPE_ACCEPT (13 | 0x0400 | 0x0100)  /* socket for accept */
756 #define BIO_TYPE_PROXY_CLIENT (14 | 0x0200)     /* client proxy BIO */
757 #define BIO_TYPE_PROXY_SERVER (15 | 0x0200)     /* server proxy BIO */
758 #define BIO_TYPE_NBIO_TEST (16 | 0x0200)        /* server proxy BIO */
759 #define BIO_TYPE_NULL_FILTER (17 | 0x0200)
760 #define BIO_TYPE_BER (18 | 0x0200)        /* BER -> bin filter */
761 #define BIO_TYPE_BIO (19 | 0x0400)        /* (half a) BIO pair */
762 #define BIO_TYPE_LINEBUFFER (20 | 0x0200) /* filter */
763 #define BIO_TYPE_DGRAM (21 | 0x0400 | 0x0100)
764 #define BIO_TYPE_ASN1 (22 | 0x0200) /* filter */
765 #define BIO_TYPE_COMP (23 | 0x0200) /* filter */
766 
767 #define BIO_TYPE_DESCRIPTOR 0x0100 /* socket, fd, connect or accept */
768 #define BIO_TYPE_FILTER 0x0200
769 #define BIO_TYPE_SOURCE_SINK 0x0400
770 
771 struct bio_method_st {
772   int type;
773   const char *name;
774   int (*bwrite)(BIO *, const char *, int);
775   int (*bread)(BIO *, char *, int);
776   /* TODO(fork): remove bputs. */
777   int (*bputs)(BIO *, const char *);
778   int (*bgets)(BIO *, char *, int);
779   long (*ctrl)(BIO *, int, long, void *);
780   int (*create)(BIO *);
781   int (*destroy)(BIO *);
782   long (*callback_ctrl)(BIO *, int, bio_info_cb);
783 };
784 
785 struct bio_st {
786   const BIO_METHOD *method;
787   /* bio, mode, argp, argi, argl, ret */
788   long (*callback)(struct bio_st *, int, const char *, int, long, long);
789   char *cb_arg; /* first argument for the callback */
790 
791   /* init is non-zero if this |BIO| has been initialised. */
792   int init;
793   /* shutdown is often used by specific |BIO_METHOD|s to determine whether
794    * they own some underlying resource. This flag can often by controlled by
795    * |BIO_set_close|. For example, whether an fd BIO closes the underlying fd
796    * when it, itself, is closed. */
797   int shutdown;
798   int flags;
799   int retry_reason;
800   /* num is a BIO-specific value. For example, in fd BIOs it's used to store a
801    * file descriptor. */
802   int num;
803   CRYPTO_refcount_t references;
804   void *ptr;
805   /* next_bio points to the next |BIO| in a chain. This |BIO| owns a reference
806    * to |next_bio|. */
807   struct bio_st *next_bio; /* used by filter BIOs */
808   size_t num_read, num_write;
809 };
810 
811 #define BIO_C_SET_CONNECT			100
812 #define BIO_C_DO_STATE_MACHINE			101
813 #define BIO_C_SET_NBIO				102
814 #define BIO_C_SET_PROXY_PARAM			103
815 #define BIO_C_SET_FD				104
816 #define BIO_C_GET_FD				105
817 #define BIO_C_SET_FILE_PTR			106
818 #define BIO_C_GET_FILE_PTR			107
819 #define BIO_C_SET_FILENAME			108
820 #define BIO_C_SET_SSL				109
821 #define BIO_C_GET_SSL				110
822 #define BIO_C_SET_MD				111
823 #define BIO_C_GET_MD				112
824 #define BIO_C_GET_CIPHER_STATUS			113
825 #define BIO_C_SET_BUF_MEM			114
826 #define BIO_C_GET_BUF_MEM_PTR			115
827 #define BIO_C_GET_BUFF_NUM_LINES		116
828 #define BIO_C_SET_BUFF_SIZE			117
829 #define BIO_C_SET_ACCEPT			118
830 #define BIO_C_SSL_MODE				119
831 #define BIO_C_GET_MD_CTX			120
832 #define BIO_C_GET_PROXY_PARAM			121
833 #define BIO_C_SET_BUFF_READ_DATA		122 /* data to read first */
834 #define BIO_C_GET_CONNECT			123
835 #define BIO_C_GET_ACCEPT			124
836 #define BIO_C_SET_SSL_RENEGOTIATE_BYTES		125
837 #define BIO_C_GET_SSL_NUM_RENEGOTIATES		126
838 #define BIO_C_SET_SSL_RENEGOTIATE_TIMEOUT	127
839 #define BIO_C_FILE_SEEK				128
840 #define BIO_C_GET_CIPHER_CTX			129
841 #define BIO_C_SET_BUF_MEM_EOF_RETURN		130/*return end of input value*/
842 #define BIO_C_SET_BIND_MODE			131
843 #define BIO_C_GET_BIND_MODE			132
844 #define BIO_C_FILE_TELL				133
845 #define BIO_C_GET_SOCKS				134
846 #define BIO_C_SET_SOCKS				135
847 
848 #define BIO_C_SET_WRITE_BUF_SIZE		136/* for BIO_s_bio */
849 #define BIO_C_GET_WRITE_BUF_SIZE		137
850 #define BIO_C_GET_WRITE_GUARANTEE		140
851 #define BIO_C_GET_READ_REQUEST			141
852 #define BIO_C_SHUTDOWN_WR			142
853 #define BIO_C_NREAD0				143
854 #define BIO_C_NREAD				144
855 #define BIO_C_NWRITE0				145
856 #define BIO_C_NWRITE				146
857 #define BIO_C_RESET_READ_REQUEST		147
858 #define BIO_C_SET_MD_CTX			148
859 
860 #define BIO_C_SET_PREFIX			149
861 #define BIO_C_GET_PREFIX			150
862 #define BIO_C_SET_SUFFIX			151
863 #define BIO_C_GET_SUFFIX			152
864 
865 #define BIO_C_SET_EX_ARG			153
866 #define BIO_C_GET_EX_ARG			154
867 
868 
869 #if defined(__cplusplus)
870 }  /* extern C */
871 #endif
872 
873 #define BIO_F_BIO_callback_ctrl 100
874 #define BIO_F_BIO_ctrl 101
875 #define BIO_F_BIO_new 102
876 #define BIO_F_BIO_new_file 103
877 #define BIO_F_BIO_new_mem_buf 104
878 #define BIO_F_BIO_zero_copy_get_read_buf 105
879 #define BIO_F_BIO_zero_copy_get_read_buf_done 106
880 #define BIO_F_BIO_zero_copy_get_write_buf 107
881 #define BIO_F_BIO_zero_copy_get_write_buf_done 108
882 #define BIO_F_bio_io 109
883 #define BIO_F_bio_make_pair 110
884 #define BIO_F_bio_write 111
885 #define BIO_F_buffer_ctrl 112
886 #define BIO_F_conn_ctrl 113
887 #define BIO_F_conn_state 114
888 #define BIO_F_file_ctrl 115
889 #define BIO_F_file_read 116
890 #define BIO_F_mem_write 117
891 #define BIO_F_BIO_printf 118
892 #define BIO_R_BAD_FOPEN_MODE 100
893 #define BIO_R_BROKEN_PIPE 101
894 #define BIO_R_CONNECT_ERROR 102
895 #define BIO_R_ERROR_SETTING_NBIO 103
896 #define BIO_R_INVALID_ARGUMENT 104
897 #define BIO_R_IN_USE 105
898 #define BIO_R_KEEPALIVE 106
899 #define BIO_R_NBIO_CONNECT_ERROR 107
900 #define BIO_R_NO_HOSTNAME_SPECIFIED 108
901 #define BIO_R_NO_PORT_SPECIFIED 109
902 #define BIO_R_NO_SUCH_FILE 110
903 #define BIO_R_NULL_PARAMETER 111
904 #define BIO_R_SYS_LIB 112
905 #define BIO_R_UNABLE_TO_CREATE_SOCKET 113
906 #define BIO_R_UNINITIALIZED 114
907 #define BIO_R_UNSUPPORTED_METHOD 115
908 #define BIO_R_WRITE_TO_READ_ONLY_BIO 116
909 
910 #endif  /* OPENSSL_HEADER_BIO_H */
911