BIO_find_type(3)BIO_find_type(3)NAME
BIO_find_type, BIO_next - BIO chain traversal
SYNOPSIS
#include <openssl/bio.h>
BIO * BIO_find_type(
BIO *b,
int bio_type ); BIO * BIO_next(
BIO *b ); #define
BIO_method_type(b) ((b)->method->type)
#define BIO_TYPE_NONE 0 #define
BIO_TYPE_MEM (1|0x0400) #define
BIO_TYPE_FILE (2|0x0400)
#define BIO_TYPE_FD (4|0x0400|0x0100) #define
BIO_TYPE_SOCKET (5|0x0400|0x0100) #define
BIO_TYPE_NULL (6|0x0400) #define
BIO_TYPE_SSL (7|0x0200) #define BIO_TYPE_MD (8|0x0200)
#define BIO_TYPE_BUFFER (9|0x0200) #define
BIO_TYPE_CIPHER (10|0x0200) #define
BIO_TYPE_BASE64 (11|0x0200) #define BIO_TYPE_CON‐
NECT (12|0x0400|0x0100) #define
BIO_TYPE_ACCEPT (13|0x0400|0x0100) #define
BIO_TYPE_PROXY_CLIENT (14|0x0200) #define
BIO_TYPE_PROXY_SERVER (15|0x0200) #define
BIO_TYPE_NBIO_TEST (16|0x0200) #define BIO_TYPE_NULL_FIL‐
TER (17|0x0200) #define BIO_TYPE_BER (18|0x0200) #define
BIO_TYPE_BIO (19|0x0400)
#define BIO_TYPE_DESCRIPTOR 0x0100 #define BIO_TYPE_FIL‐
TER 0x0200 #define BIO_TYPE_SOURCE_SINK 0x0400
DESCRIPTION
The BIO_find_type() function searches for a BIO of a given type in a
chain, starting at BIO b. If type is a specific type, such as
BIO_TYPE_MEM, then a search is made for a BIO of that type. If type is
a general type, such as BIO_TYPE_SOURCE_SINK, then the next matching
BIO of the given general type is sought. The BIO_find_type()function
returns the next matching BIO or NULL if none is found.
Note
Some BIO_TYPE_* types do not have corresponding BIO implementations.
The BIO_next()function returns the next BIO in a chain. It can be used
to traverse all BIOs in a chain or used in conjunction with the
BIO_find_type() function to find all BIOs of a certain type.
The BIO_method_type() function returns the type of a BIO.
NOTES
The BIO_next() function was added to OpenSSL 0.9.6 to provide a clean
way to traverse a BIO chain or find multiple matches using the
BIO_find_type() function. Previous versions used the following:
next = bio->next_bio;
RESTRICTIONS
The BIO_find_type() function in OpenSSL 0.9.5a and earlier could not be
safely passed a NULL pointer for the b argument.
RETURN VALUES
The BIO_find_type() function returns a matching BIO or NULL for no
match.
The BIO_next() function returns the next BIO in a chain.
The BIO_method_type() function returns the type of the BIO b.
EXAMPLE
Traverse a chain looking for digest BIOs:
BIO *btmp;
btmp = in_bio; /* in_bio is chain to search through */
do {
btmp = BIO_find_type(btmp, BIO_TYPE_MD); if(btmp == NULL)
break; /* Not found */ /* btmp is a digest BIO, do something with
it ...*/
...
btmp = BIO_next(btmp);
} while(btmp);
SEE ALSO
TBA
BIO_find_type(3)