1.\" $OpenBSD: BIO_get_data.3,v 1.8 2023/11/16 20:27:43 schwarze Exp $ 2.\" full merge up to: OpenSSL 24a535ea Sep 22 13:14:20 2020 +0100 3.\" 4.\" This file is a derived work. 5.\" The changes are covered by the following Copyright and license: 6.\" 7.\" Copyright (c) 2018, 2022 Ingo Schwarze <schwarze@openbsd.org> 8.\" 9.\" Permission to use, copy, modify, and distribute this software for any 10.\" purpose with or without fee is hereby granted, provided that the above 11.\" copyright notice and this permission notice appear in all copies. 12.\" 13.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 14.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 15.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 16.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 17.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 18.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 19.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 20.\" 21.\" The original file was written by Matt Caswell <matt@openssl.org>. 22.\" Copyright (c) 2016 The OpenSSL Project. All rights reserved. 23.\" 24.\" Redistribution and use in source and binary forms, with or without 25.\" modification, are permitted provided that the following conditions 26.\" are met: 27.\" 28.\" 1. Redistributions of source code must retain the above copyright 29.\" notice, this list of conditions and the following disclaimer. 30.\" 31.\" 2. 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Redistributions of any form whatsoever must retain the following 51.\" acknowledgment: 52.\" "This product includes software developed by the OpenSSL Project 53.\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" 54.\" 55.\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 56.\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 57.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 58.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 59.\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 60.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 61.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 62.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 63.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 64.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 65.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 66.\" OF THE POSSIBILITY OF SUCH DAMAGE. 67.\" 68.Dd $Mdocdate: November 16 2023 $ 69.Dt BIO_GET_DATA 3 70.Os 71.Sh NAME 72.Nm BIO_set_data , 73.Nm BIO_get_data , 74.Nm BIO_set_flags , 75.Nm BIO_clear_flags , 76.Nm BIO_test_flags , 77.Nm BIO_get_flags , 78.Nm BIO_set_retry_read , 79.Nm BIO_set_retry_write , 80.Nm BIO_set_retry_special , 81.Nm BIO_clear_retry_flags , 82.Nm BIO_get_retry_flags , 83.Nm BIO_copy_next_retry , 84.Nm BIO_set_init , 85.Nm BIO_get_init , 86.Nm BIO_set_shutdown , 87.Nm BIO_get_shutdown 88.Nd manage BIO state information 89.Sh SYNOPSIS 90.In openssl/bio.h 91.Ft void 92.Fo BIO_set_data 93.Fa "BIO *a" 94.Fa "void *ptr" 95.Fc 96.Ft void * 97.Fo BIO_get_data 98.Fa "BIO *a" 99.Fc 100.Ft void 101.Fo BIO_set_flags 102.Fa "BIO *a" 103.Fa "int flags" 104.Fc 105.Ft void 106.Fo BIO_clear_flags 107.Fa "BIO *a" 108.Fa "int flags" 109.Fc 110.Ft int 111.Fo BIO_test_flags 112.Fa "const BIO *a" 113.Fa "int flags" 114.Fc 115.Ft int 116.Fo BIO_get_flags 117.Fa "const BIO *a" 118.Fc 119.Ft void 120.Fo BIO_set_retry_read 121.Fa "BIO *a" 122.Fc 123.Ft void 124.Fo BIO_set_retry_write 125.Fa "BIO *a" 126.Fc 127.Ft void 128.Fo BIO_set_retry_special 129.Fa "BIO *a" 130.Fc 131.Ft void 132.Fo BIO_clear_retry_flags 133.Fa "BIO *a" 134.Fc 135.Ft int 136.Fo BIO_get_retry_flags 137.Fa "BIO *a" 138.Fc 139.Ft void 140.Fo BIO_copy_next_retry 141.Fa "BIO *a" 142.Fc 143.Ft void 144.Fo BIO_set_init 145.Fa "BIO *a" 146.Fa "int init" 147.Fc 148.Ft int 149.Fo BIO_get_init 150.Fa "BIO *a" 151.Fc 152.Ft void 153.Fo BIO_set_shutdown 154.Fa "BIO *a" 155.Fa "int shutdown" 156.Fc 157.Ft int 158.Fo BIO_get_shutdown 159.Fa "BIO *a" 160.Fc 161.Sh DESCRIPTION 162These functions are mainly useful when implementing a custom BIO. 163.Pp 164The 165.Fn BIO_set_data 166function associates the custom data pointed to by 167.Fa ptr 168with the 169.Fa "BIO a" . 170This data can subsequently be retrieved via a call to 171.Fn BIO_get_data . 172This can be used by custom BIOs for storing implementation specific 173information. 174.Pp 175.Fn BIO_set_flags 176sets all the bits contained in the 177.Fa flags 178argument in the flags stored in 179.Fa a . 180The value of a flag neither changes when it is already set in 181.Fa a 182nor when it is unset in the 183.Fa flags 184argument. 185.Pp 186.Fn BIO_clear_flags 187clears all the bits contained in the 188.Fa flags 189argument from the flags stored in 190.Fa a . 191The value of a flag neither changes when it is already unset in 192.Fa a 193nor when it is unset in the 194.Fa flags 195argument. 196.Pp 197.Fn BIO_test_flags 198checks whether any of the bits contained in the 199.Fa flags 200argument are set in the flags stored in 201.Fa a . 202Application programs usually call macros like those documented in 203.Xr BIO_should_retry 3 204rather than calling 205.Fn BIO_test_flags 206directly. 207Flag bits correspond to accessor macros as follows: 208.Pp 209.Bl -tag -width BIO_FLAGS_SHOULD_RETRY -compact 210.It Dv BIO_FLAGS_READ 211.Xr BIO_should_read 3 212.It Dv BIO_FLAGS_WRITE 213.Xr BIO_should_write 3 214.It Dv BIO_FLAGS_IO_SPECIAL 215.Xr BIO_should_io_special 3 216.It Dv BIO_FLAGS_RWS 217.Xr BIO_retry_type 3 218.It Dv BIO_FLAGS_SHOULD_RETRY 219.Xr BIO_should_retry 3 220.It Dv BIO_FLAGS_BASE64_NO_NL 221see 222.Xr BIO_f_base64 3 223.It Dv BIO_FLAGS_MEM_RDONLY 224see 225.Xr BIO_s_mem 3 226.El 227.Pp 228In particular, 229.Dv BIO_FLAGS_RWS 230is the bitwise OR of 231.Dv BIO_FLAGS_READ , 232.Dv BIO_FLAGS_WRITE , 233and 234.Dv BIO_FLAGS_IO_SPECIAL . 235.Pp 236.Fn BIO_set_retry_read , 237.Fn BIO_set_retry_write , 238and 239.Fn BIO_set_retry_special 240set the 241.Dv BIO_FLAGS_READ , 242.Dv BIO_FLAGS_WRITE , 243and 244.Dv BIO_FLAGS_IO_SPECIAL 245flag bit in 246.Fa a , 247respectively. 248They all set the 249.Dv BIO_FLAGS_SHOULD_RETRY 250flag bit, too. 251.Pp 252.Fn BIO_clear_retry_flags 253clears the flag bits 254.Dv BIO_FLAGS_READ , 255.Dv BIO_FLAGS_WRITE , 256.Dv BIO_FLAGS_IO_SPECIAL , 257and 258.Dv BIO_FLAGS_SHOULD_RETRY 259in 260.Fa a . 261.Pp 262.Fn BIO_copy_next_retry 263copies retry-related state data from the BIO that follows 264.Fa a 265in its chain to 266.Fa a , 267that is, the data accessible with 268.Fn BIO_get_retry_flags 269and 270.Xr BIO_get_retry_reason 3 . 271Flags which are already set in 272.Fa a 273are not cleared. 274Before calling 275.Fn BIO_copy_next_retry , 276making sure that 277.Fa a 278is not the last BIO in its chain is the responsibility of the caller, 279for example by checking that 280.Xr BIO_next 3 281does not return 282.Dv NULL . 283.Pp 284The 285.Fn BIO_set_init 286function sets the 287.Fa init 288flag in 289.Fa a 290to the specified value. 291A non-zero value indicates that initialisation is complete, 292whilst zero indicates that it is not. 293Often initialisation will complete 294during initial construction of the BIO. 295For some BIOs however, initialisation may not be complete until 296additional steps have been taken, for example through calling custom 297ctrls. 298.Pp 299The 300.Fn BIO_set_shutdown 301and 302.Fn BIO_get_shutdown 303functions are low-level interfaces to forcefully set and get the 304.Fa shutdown 305flag of 306.Fa a , 307circumventing type-dependent sanity checks, 308exclusively intended for implementing a new BIO type. 309The 310.Fa shutdown 311argument must be either 312.Dv BIO_CLOSE 313or 314.Dv BIO_NOCLOSE . 315When merely using a 316.Vt BIO 317object, call 318.Xr BIO_set_close 3 319and 320.Xr BIO_get_close 3 321instead. 322.Pp 323.Fn BIO_get_flags , 324.Fn BIO_set_retry_read , 325.Fn BIO_set_retry_write , 326.Fn BIO_set_retry_special , 327.Fn BIO_clear_retry_flags , 328and 329.Fn BIO_get_retry_flags 330are implemented as macros. 331.Sh RETURN VALUES 332.Fn BIO_get_data 333returns a pointer to the implementation specific custom data associated 334with 335.Fa a , 336or 337.Dv NULL 338if none is set. 339.Pp 340.Fn BIO_test_flags 341returns the bitwise AND of the 342.Fa flags 343argument and the flags stored in 344.Fa a . 345Consequently, it returns a non-zero value 346if and only if at least one of the requested 347.Fa flags 348is set. 349.Pp 350.Fn BIO_get_flags 351returns all the flags currently stored in 352.Fa a . 353.Pp 354.Fn BIO_get_retry_flags 355returns the bitwise AND of 356.Pq Dv BIO_FLAGS_RWS | BIO_FLAGS_SHOULD_RETRY 357and the flags stored in 358.Fa a . 359.Pp 360.Fn BIO_get_init 361returns the value of the init flag of 362.Fa a . 363.Pp 364.Fn BIO_get_shutdown 365returns the value previously set with 366.Fn BIO_set_shutdown 367or with 368.Xr BIO_set_close 3 . 369.Sh SEE ALSO 370.Xr BIO_meth_new 3 , 371.Xr BIO_new 3 , 372.Xr BIO_set_close 3 , 373.Xr BIO_should_retry 3 374.Sh HISTORY 375.Fn BIO_set_flags , 376.Fn BIO_clear_flags , 377.Fn BIO_set_retry_read , 378.Fn BIO_set_retry_write , 379.Fn BIO_set_retry_special , 380.Fn BIO_clear_retry_flags , 381and 382.Fn BIO_get_retry_flags 383first appeared in SSLeay 0.8.0, 384.Fn BIO_copy_next_retry 385in SSLeay 0.8.1, and 386.Fn BIO_get_flags 387in SSLeay 0.9.0. 388These functions have been available since 389.Ox 2.4 . 390.Pp 391.Fn BIO_test_flags 392first appeared in OpenSSL 0.9.8e and has been available since 393.Ox 4.5 . 394.Pp 395.Fn BIO_set_data , 396.Fn BIO_get_data , 397.Fn BIO_set_init , 398.Fn BIO_set_shutdown , 399and 400.Fn BIO_get_shutdown 401first appeared in OpenSSL 1.1.0 and have been available since 402.Ox 6.3 . 403.Pp 404.Fn BIO_get_init 405first appeared in OpenSSL 1.1.0 and has been available since 406.Ox 7.1 . 407