BIO_meth_new3ssl
Routines to build up bio methods
Usage
#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_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_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_set_puts(BIO_METHOD *biom, int (*puts)(BIO *, const char *));int BIO_meth_set_gets(BIO_METHOD *biom,int (*gets)(BIO *, char *, int));int BIO_meth_set_ctrl(BIO_METHOD *biom,long (*ctrl)(BIO *, int, long, void *));int BIO_meth_set_create(BIO_METHOD *biom, int (*create)(BIO *));int BIO_meth_set_destroy(BIO_METHOD *biom, int (*destroy)(BIO *));int BIO_meth_set_callback_ctrl(BIO_METHOD *biom,long (*callback_ctrl)(BIO *, int, BIO_info_cb *));int BIO_meth_set_sendmmsg(BIO_METHOD *biom,ossl_ssize_t (*f) (BIO *, BIO_MSG *, size_t,size_t, uint64_t));int BIO_meth_set_recvmmsg(BIO_METHOD *biom,ossl_ssize_t (*f) (BIO *, BIO_MSG *, size_t,size_t, uint64_t));
The following functions have been deprecated since OpenSSL 3.5:
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_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_get_puts(const BIO_METHOD *biom))(BIO *, const char *);int (*BIO_meth_get_gets(const BIO_METHOD *biom))(BIO *, char *, int);long (*BIO_meth_get_ctrl(const BIO_METHOD *biom))(BIO *, int, long, void *);int (*BIO_meth_get_create(const BIO_METHOD *bion))(BIO *);int (*BIO_meth_get_destroy(const BIO_METHOD *biom))(BIO *);long (*BIO_meth_get_callback_ctrl(const BIO_METHOD *biom))(BIO *, int, BIO_info_cb *);ossl_ssize_t (*BIO_meth_get_sendmmsg(const BIO_METHOD *biom))(BIO *,BIO_MSG *,size_t,size_t,uint64_t);ossl_ssize_t (*BIO_meth_get_recvmmsg(const BIO_METHOD *biom))(BIO *,BIO_MSG *,size_t,size_t,uint64_t);
Overview
The BIO_METHOD type is a structure used for the implementation of new BIO types. It provides a set of functions used by OpenSSL for the implementation of the various BIO capabilities. See the bio(7) page for more information.
BIO_meth_new() creates a new BIO_METHOD structure that contains a type identifier type and a string that represents its name. type can be set to either BIO_TYPE_NONE or via BIO_get_new_index() if a unique type is required for searching (See BIO_find_type(3))
Note that BIO_get_new_index() can only be used 127 times before it returns an error.
The set of standard OpenSSL provided BIO types is provided in <openssl/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(3) page for more information.
BIO_meth_free() destroys a BIO_METHOD structure and frees up any memory associated with it. If the argument is NULL, nothing is done.
BIO_meth_get_write_ex() and BIO_meth_set_write_ex() 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_ex() or BIO_write(). The parameters for the function have the same meaning as for BIO_write_ex(). Older code may call BIO_meth_get_write() and BIO_meth_set_write() instead. Applications should not call both BIO_meth_set_write_ex() and BIO_meth_set_write() or call BIO_meth_get_write() when the function was set with BIO_meth_set_write_ex().
BIO_meth_get_read_ex() and BIO_meth_set_read_ex() 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_ex() or BIO_read(). The parameters for the function have the same meaning as for BIO_read_ex(). Older code may call BIO_meth_get_read() and BIO_meth_set_read() instead. Applications should not call both BIO_meth_set_read_ex() and BIO_meth_set_read() or call BIO_meth_get_read() when the function was set with BIO_meth_set_read_ex().
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(3) 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. If a create function is set, BIO_new() will not mark the BIO as initialised on allocation. BIO_set_init(3) must then be called either by the create function, or later, by a BIO ctrl function, once BIO initialisation is complete.
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().
BIO_meth_get_sendmmsg(), BIO_meth_set_sendmmsg(), BIO_meth_get_recvmmsg() and BIO_meth_set_recvmmsg() get and set the functions used for handling BIO_sendmmsg() and BIO_recvmmsg() calls respectively. See BIO_sendmmsg(3) for more information.
Return values
BIO_get_new_index() returns the new BIO type value or -1 if an error occurred.
BIO_meth_new(int type, const char *name) returns a valid BIO_METHOD or NULL if an error occurred.
The BIO_meth_set functions return 1 on success or 0 on error.
The BIO_meth_get functions return the corresponding function pointers.
Releases
6 releases since Debian 9 (Stretch); the text changed 5 times.