BIO_METH_NEW(3)

NAME
BIO_get_new_index, BIO_meth_new, BIO_meth_free, 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

SYNOPSIS
 #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(const BIO_METHOD *biom)) (BIO *, const char *, int);
 int BIO_meth_set_write(BIO_METHOD *biom,
                        int (*write) (BIO *, const char *, int));
 int (*BIO_meth_get_read(const BIO_METHOD *biom)) (BIO *, char *, int);
 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 *));

DESCRIPTION
The BIO_METHOD type is a structure used for the implementation of new BIO types. It provides a set of of functions used by OpenSSL for the implementation of the various BIO capabilities. See the bio page for more information.

BIO_meth_new() creates a new BIO_METHOD structure. It should be given a unique integer type and a string that represents its name. Use BIO_get_new_index() to get the value for type.

The set of standard OpenSSL provided BIO types is provided in bio.h. Some examples include BIO_TYPE_BUFFER and BIO_TYPE_CIPHER. Filter BIOs should have a type which have the "filter" bit set (BIO_TYPE_FILTER). Source/sink BIOs should have the "source/sink" bit set (BIO_TYPE_SOURCE_SINK). File descriptor based BIOs (e.g. socket, fd, connect, accept etc) should additionally have the "descriptor" bit set (BIO_TYPE_DESCRIPTOR). See the BIO_find_type page for more information.

BIO_meth_free() destroys a BIO_METHOD structure and frees up any memory associated with it.

BIO_meth_get_write() and BIO_meth_set_write() get and set the function used for writing arbitrary length data to the BIO respectively. This function will be called in response to the application calling BIO_write(). The parameters for the function have the same meaning as for BIO_write().

BIO_meth_get_read() and BIO_meth_set_read() get and set the function used for reading arbitrary length data from the BIO respectively. This function will be called in response to the application calling BIO_read(). The parameters for the function have the same meaning as for BIO_read().

BIO_meth_get_puts() and BIO_meth_set_puts() get and set the function used for writing a NULL terminated string to the BIO respectively. This function will be called in response to the application calling BIO_puts(). The parameters for the function have the same meaning as for BIO_puts().

BIO_meth_get_gets() and BIO_meth_set_gets() get and set the function typically used for reading a line of data from the BIO respectively (see the BIO_gets(3) page for more information). This function will be called in response to the application calling BIO_gets(). The parameters for the function have the same meaning as for BIO_gets().

BIO_meth_get_ctrl() and BIO_meth_set_ctrl() get and set the function used for processing ctrl messages in the BIO respectively. See the BIO_ctrl page for more information. This function will be called in response to the application calling BIO_ctrl(). The parameters for the function have the same meaning as for BIO_ctrl().

BIO_meth_get_create() and BIO_meth_set_create() get and set the function used for creating a new instance of the BIO respectively. This function will be called in response to the application calling BIO_new() and passing in a pointer to the current BIO_METHOD. The BIO_new() function will allocate the memory for the new BIO, and a pointer to this newly allocated structure will be passed as a parameter to the function.

BIO_meth_get_destroy() and BIO_meth_set_destroy() get and set the function used for destroying an instance of a BIO respectively. This function will be called in response to the application calling BIO_free(). A pointer to the BIO to be destroyed is passed as a parameter. The destroy function should be used for BIO specific clean up. The memory for the BIO itself should not be freed by this function.

BIO_meth_get_callback_ctrl() and BIO_meth_set_callback_ctrl() get and set the function used for processing callback ctrl messages in the BIO respectively. See the BIO_callback_ctrl(3) page for more information. This function will be called in response to the application calling BIO_callback_ctrl(). The parameters for the function have the same meaning as for BIO_callback_ctrl().

SEE ALSO
bio, BIO_find_type, BIO_ctrl, BIO_read, BIO_new

HISTORY
The functions described here were added in OpenSSL 1.1.0.

COPYRIGHT
Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.