1*2175Sjp161948=pod 2*2175Sjp161948 3*2175Sjp161948=head1 NAME 4*2175Sjp161948 5*2175Sjp161948BIO_new, BIO_set, BIO_free, BIO_vfree, BIO_free_all - BIO allocation and freeing functions 6*2175Sjp161948 7*2175Sjp161948=head1 SYNOPSIS 8*2175Sjp161948 9*2175Sjp161948 #include <openssl/bio.h> 10*2175Sjp161948 11*2175Sjp161948 BIO * BIO_new(BIO_METHOD *type); 12*2175Sjp161948 int BIO_set(BIO *a,BIO_METHOD *type); 13*2175Sjp161948 int BIO_free(BIO *a); 14*2175Sjp161948 void BIO_vfree(BIO *a); 15*2175Sjp161948 void BIO_free_all(BIO *a); 16*2175Sjp161948 17*2175Sjp161948=head1 DESCRIPTION 18*2175Sjp161948 19*2175Sjp161948The BIO_new() function returns a new BIO using method B<type>. 20*2175Sjp161948 21*2175Sjp161948BIO_set() sets the method of an already existing BIO. 22*2175Sjp161948 23*2175Sjp161948BIO_free() frees up a single BIO, BIO_vfree() also frees up a single BIO 24*2175Sjp161948but it does not return a value. Calling BIO_free() may also have some effect 25*2175Sjp161948on the underlying I/O structure, for example it may close the file being 26*2175Sjp161948referred to under certain circumstances. For more details see the individual 27*2175Sjp161948BIO_METHOD descriptions. 28*2175Sjp161948 29*2175Sjp161948BIO_free_all() frees up an entire BIO chain, it does not halt if an error 30*2175Sjp161948occurs freeing up an individual BIO in the chain. 31*2175Sjp161948 32*2175Sjp161948=head1 RETURN VALUES 33*2175Sjp161948 34*2175Sjp161948BIO_new() returns a newly created BIO or NULL if the call fails. 35*2175Sjp161948 36*2175Sjp161948BIO_set(), BIO_free() return 1 for success and 0 for failure. 37*2175Sjp161948 38*2175Sjp161948BIO_free_all() and BIO_vfree() do not return values. 39*2175Sjp161948 40*2175Sjp161948=head1 NOTES 41*2175Sjp161948 42*2175Sjp161948Some BIOs (such as memory BIOs) can be used immediately after calling 43*2175Sjp161948BIO_new(). Others (such as file BIOs) need some additional initialization, 44*2175Sjp161948and frequently a utility function exists to create and initialize such BIOs. 45*2175Sjp161948 46*2175Sjp161948If BIO_free() is called on a BIO chain it will only free one BIO resulting 47*2175Sjp161948in a memory leak. 48*2175Sjp161948 49*2175Sjp161948Calling BIO_free_all() a single BIO has the same effect as calling BIO_free() 50*2175Sjp161948on it other than the discarded return value. 51*2175Sjp161948 52*2175Sjp161948Normally the B<type> argument is supplied by a function which returns a 53*2175Sjp161948pointer to a BIO_METHOD. There is a naming convention for such functions: 54*2175Sjp161948a source/sink BIO is normally called BIO_s_*() and a filter BIO 55*2175Sjp161948BIO_f_*(); 56*2175Sjp161948 57*2175Sjp161948=head1 EXAMPLE 58*2175Sjp161948 59*2175Sjp161948Create a memory BIO: 60*2175Sjp161948 61*2175Sjp161948 BIO *mem = BIO_new(BIO_s_mem()); 62*2175Sjp161948 63*2175Sjp161948=head1 SEE ALSO 64*2175Sjp161948 65*2175Sjp161948TBA 66