BIOfindtype(3) OpenSSL BIOfindtype(3)

NAME
       BIOfindtype, BIOnext - BIO chain traversal

SYNOPSIS
        #include 

        BIO *  BIOfindtype(BIO *b,int biotype);
        BIO *  BIOnext(BIO *b);

        #define BIOmethodtype(b)             ((b)->method->type)

        #define BIOTYPENONE          0
        #define BIOTYPEMEM           (1|0x0400)
        #define BIOTYPEFILE          (2|0x0400)

        #define BIOTYPEFD            (4|0x0400|0x0100)
        #define BIOTYPESOCKET                (5|0x0400|0x0100)
        #define BIOTYPENULL          (6|0x0400)
        #define BIOTYPESSL           (7|0x0200)
        #define BIOTYPEMD            (8|0x0200)
        #define BIOTYPEBUFFER                (9|0x0200)
        #define BIOTYPECIPHER                (10|0x0200)
        #define BIOTYPEBASE64                (11|0x0200)
        #define BIOTYPECONNECT       (12|0x0400|0x0100)
        #define BIOTYPEACCEPT                (13|0x0400|0x0100)
        #define BIOTYPEPROXYCLIENT  (14|0x0200)
        #define BIOTYPEPROXYSERVER  (15|0x0200)
        #define BIOTYPENBIOTEST     (16|0x0200)
        #define BIOTYPENULLFILTER   (17|0x0200)
        #define BIOTYPEBER           (18|0x0200)
        #define BIOTYPEBIO           (19|0x0400)

        #define BIOTYPEDESCRIPTOR    0x0100
        #define BIOTYPEFILTER                0x0200
        #define BIOTYPESOURCESINK   0x0400

DESCRIPTION
       The BIOfindtype() searches for a BIO of a given type in a chain,
       starting at BIO bb. If ttyyppee is a specific type (such as BIOTYPEMEM)
       then a search is made for a BIO of that type. If ttyyppee is a general type
       (such as BBIIOOTTYYPPEESSOOUURRCCEESSIINNKK) then the next matching BIO of the given
       general type is searched for. BIOfindtype() returns the next matching
       BIO or NULL if none is found.

       Note: not all the BBIIOOTTYYPPEE** types above have corresponding BIO
       implementations.

       BIOnext() returns the next BIO in a chain. It can be used to traverse
       all BIOs in a chain or used in conjunction with BIOfindtype() to find
       all BIOs of a certain type.

       BIOmethodtype() returns the type of a BIO.

RETURN VALUES
       BIOfindtype() returns a matching BIO or NULL for no match.

       BIOnext() returns the next BIO in a chain.

       BIOmethodtype() returns the type of the BIO bb.

NNOOTTEESS
       BIOnext() was added to OpenSSL 0.9.6 to provide a 'clean' way to
       traverse a BIO chain or find multiple matches using BIOfindtype().
       Previous versions had to use:

        next = bio->nextbio;

BUGS
       BIOfindtype() in OpenSSL 0.9.5a and earlier could not be safely
       passed a NULL pointer for the bb argument.

EEXXAAMMPPLLEE
       Traverse a chain looking for digest BIOs:

        BIO *btmp;
        btmp = inbio; /* inbio is chain to search through */

        do {
               btmp = BIOfindtype(btmp, BIOTYPEMD);
               if(btmp == NULL) break; /* Not found */
               /* btmp is a digest BIO, do something with it ...*/
               ...

               btmp = BIOnext(btmp);
        } while(btmp);

SEE ALSO
       TBA



0.9.7l                            2000-09-14                  BIOfindtype(3)