path: root/secure/lib/libcrypto/man/man3/BIO_meth_new.3

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.\" ========================================================================
.\"
.IX Title "BIO_METH_NEW 3"
.TH BIO_METH_NEW 3 "2022-06-21" "1.1.1p" "OpenSSL"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
BIO_get_new_index, BIO_meth_new, BIO_meth_free, BIO_meth_get_read_ex, BIO_meth_set_read_ex, BIO_meth_get_write_ex, BIO_meth_set_write_ex, BIO_meth_get_write, BIO_meth_set_write, BIO_meth_get_read, BIO_meth_set_read, BIO_meth_get_puts, BIO_meth_set_puts, BIO_meth_get_gets, BIO_meth_set_gets, BIO_meth_get_ctrl, BIO_meth_set_ctrl, BIO_meth_get_create, BIO_meth_set_create, BIO_meth_get_destroy, BIO_meth_set_destroy, BIO_meth_get_callback_ctrl, BIO_meth_set_callback_ctrl \- Routines to build up BIO methods
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\& #include <openssl/bio.h>
\&
\& int BIO_get_new_index(void);
\&
\& BIO_METHOD *BIO_meth_new(int type, const char *name);
\&
\& void BIO_meth_free(BIO_METHOD *biom);
\&
\& int (*BIO_meth_get_write_ex(const BIO_METHOD *biom))(BIO *, const char *, size_t,
\&                                                size_t *);
\& int (*BIO_meth_get_write(const BIO_METHOD *biom))(BIO *, const char *, int);
\& int BIO_meth_set_write_ex(BIO_METHOD *biom,
\&                           int (*bwrite)(BIO *, const char *, size_t, size_t *));
\& int BIO_meth_set_write(BIO_METHOD *biom,
\&                        int (*write)(BIO *, const char *, int));
\&
\& int (*BIO_meth_get_read_ex(const BIO_METHOD *biom))(BIO *, char *, size_t, size_t *);
\& int (*BIO_meth_get_read(const BIO_METHOD *biom))(BIO *, char *, int);
\& int BIO_meth_set_read_ex(BIO_METHOD *biom,
\&                          int (*bread)(BIO *, char *, size_t, size_t *));
\& int BIO_meth_set_read(BIO_METHOD *biom, int (*read)(BIO *, char *, int));
\&
\& int (*BIO_meth_get_puts(const BIO_METHOD *biom))(BIO *, const char *);
\& int BIO_meth_set_puts(BIO_METHOD *biom, int (*puts)(BIO *, const char *));
\&
\& int (*BIO_meth_get_gets(const BIO_METHOD *biom))(BIO *, char *, int);
\& int BIO_meth_set_gets(BIO_METHOD *biom,
\&                       int (*gets)(BIO *, char *, int));
\&
\& long (*BIO_meth_get_ctrl(const BIO_METHOD *biom))(BIO *, int, long, void *);
\& int BIO_meth_set_ctrl(BIO_METHOD *biom,
\&                       long (*ctrl)(BIO *, int, long, void *));
\&
\& int (*BIO_meth_get_create(const BIO_METHOD *bion))(BIO *);
\& int BIO_meth_set_create(BIO_METHOD *biom, int (*create)(BIO *));
\&
\& int (*BIO_meth_get_destroy(const BIO_METHOD *biom))(BIO *);
\& int BIO_meth_set_destroy(BIO_METHOD *biom, int (*destroy)(BIO *));
\&
\& long (*BIO_meth_get_callback_ctrl(const BIO_METHOD *biom))(BIO *, int, BIO_info_cb *);
\& int BIO_meth_set_callback_ctrl(BIO_METHOD *biom,
\&                                long (*callback_ctrl)(BIO *, int, BIO_info_cb *));
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
The \fB\s-1BIO_METHOD\s0\fR type is a structure used for the implementation of new \s-1BIO\s0
types. It provides a set of functions used by OpenSSL for the implementation
of the various \s-1BIO\s0 capabilities. See the bio page for more information.
.PP
\&\fBBIO_meth_new()\fR creates a new \fB\s-1BIO_METHOD\s0\fR structure. It should be given a
unique integer \fBtype\fR and a string that represents its \fBname\fR.
Use \fBBIO_get_new_index()\fR to get the value for \fBtype\fR.
.PP
The set of
standard OpenSSL provided \s-1BIO\s0 types is provided in \fBbio.h\fR. Some examples
include \fB\s-1BIO_TYPE_BUFFER\s0\fR and \fB\s-1BIO_TYPE_CIPHER\s0\fR. Filter BIOs should have a
type which have the \*(L"filter\*(R" bit set (\fB\s-1BIO_TYPE_FILTER\s0\fR). Source/sink BIOs
should have the \*(L"source/sink\*(R" bit set (\fB\s-1BIO_TYPE_SOURCE_SINK\s0\fR). File descriptor
based BIOs (e.g. socket, fd, connect, accept etc) should additionally have the
\&\*(L"descriptor\*(R" bit set (\fB\s-1BIO_TYPE_DESCRIPTOR\s0\fR). See the BIO_find_type page for
more information.
.PP
\&\fBBIO_meth_free()\fR destroys a \fB\s-1BIO_METHOD\s0\fR structure and frees up any memory
associated with it.
.PP
\&\fBBIO_meth_get_write_ex()\fR and \fBBIO_meth_set_write_ex()\fR get and set the function
used for writing arbitrary length data to the \s-1BIO\s0 respectively. This function
will be called in response to the application calling \fBBIO_write_ex()\fR or
\&\fBBIO_write()\fR. The parameters for the function have the same meaning as for
\&\fBBIO_write_ex()\fR. Older code may call \fBBIO_meth_get_write()\fR and
\&\fBBIO_meth_set_write()\fR instead. Applications should not call both
\&\fBBIO_meth_set_write_ex()\fR and \fBBIO_meth_set_write()\fR or call \fBBIO_meth_get_write()\fR
when the function was set with \fBBIO_meth_set_write_ex()\fR.
.PP
\&\fBBIO_meth_get_read_ex()\fR and \fBBIO_meth_set_read_ex()\fR get and set the function used
for reading arbitrary length data from the \s-1BIO\s0 respectively. This function will
be called in response to the application calling \fBBIO_read_ex()\fR or \fBBIO_read()\fR.
The parameters for the function have the same meaning as for \fBBIO_read_ex()\fR.
Older code may call \fBBIO_meth_get_read()\fR and \fBBIO_meth_set_read()\fR instead.
Applications should not call both \fBBIO_meth_set_read_ex()\fR and \fBBIO_meth_set_read()\fR
or call \fBBIO_meth_get_read()\fR when the function was set with
\&\fBBIO_meth_set_read_ex()\fR.
.PP
\&\fBBIO_meth_get_puts()\fR and \fBBIO_meth_set_puts()\fR get and set the function used for
writing a \s-1NULL\s0 terminated string to the \s-1BIO\s0 respectively. This function will be
called in response to the application calling \fBBIO_puts()\fR. The parameters for
the function have the same meaning as for \fBBIO_puts()\fR.
.PP
\&\fBBIO_meth_get_gets()\fR and \fBBIO_meth_set_gets()\fR get and set the function typically
used for reading a line of data from the \s-1BIO\s0 respectively (see the \fBBIO_gets\fR\|(3)
page for more information). This function will be called in response to the
application calling \fBBIO_gets()\fR. The parameters for the function have the same
meaning as for \fBBIO_gets()\fR.
.PP
\&\fBBIO_meth_get_ctrl()\fR and \fBBIO_meth_set_ctrl()\fR get and set the function used for
processing ctrl messages in the \s-1BIO\s0 respectively. See the BIO_ctrl page for
more information. This function will be called in response to the application
calling \fBBIO_ctrl()\fR. The parameters for the function have the same meaning as for
\&\fBBIO_ctrl()\fR.
.PP
\&\fBBIO_meth_get_create()\fR and \fBBIO_meth_set_create()\fR get and set the function used
for creating a new instance of the \s-1BIO\s0 respectively. This function will be
called in response to the application calling \fBBIO_new()\fR and passing
in a pointer to the current \s-1BIO_METHOD.\s0 The \fBBIO_new()\fR function will allocate the
memory for the new \s-1BIO,\s0 and a pointer to this newly allocated structure will
be passed as a parameter to the function.
.PP
\&\fBBIO_meth_get_destroy()\fR and \fBBIO_meth_set_destroy()\fR get and set the function used
for destroying an instance of a \s-1BIO\s0 respectively. This function will be
called in response to the application calling \fBBIO_free()\fR. A pointer to the \s-1BIO\s0
to be destroyed is passed as a parameter. The destroy function should be used
for \s-1BIO\s0 specific clean up. The memory for the \s-1BIO\s0 itself should not be freed by
this function.
.PP
\&\fBBIO_meth_get_callback_ctrl()\fR and \fBBIO_meth_set_callback_ctrl()\fR get and set the
function used for processing callback ctrl messages in the \s-1BIO\s0 respectively. See
the \fBBIO_callback_ctrl\fR\|(3) page for more information. This function will be called
in response to the application calling \fBBIO_callback_ctrl()\fR. The parameters for
the function have the same meaning as for \fBBIO_callback_ctrl()\fR.
.SH "RETURN VALUES"
.IX Header "RETURN VALUES"
\&\fBBIO_get_new_index()\fR returns the new \s-1BIO\s0 type value or \-1 if an error occurred.
.PP
BIO_meth_new(int type, const char *name) returns a valid \fB\s-1BIO_METHOD\s0\fR or \s-1NULL\s0
if an error occurred.
.PP
The \fBBIO_meth_set\fR functions return 1 on success or 0 on error.
.PP
The \fBBIO_meth_get\fR functions return the corresponding function pointers.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
bio, BIO_find_type, BIO_ctrl, BIO_read_ex, BIO_new
.SH "HISTORY"
.IX Header "HISTORY"
The functions described here were added in OpenSSL 1.1.0.
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 2016\-2018 The OpenSSL Project Authors. All Rights Reserved.
.PP
Licensed under the OpenSSL license (the \*(L"License\*(R").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file \s-1LICENSE\s0 in the source distribution or at
<https://www.openssl.org/source/license.html>.