=pod

=head1 NAME

BIO_f_null - null filter

=head1 SYNOPSIS

 #include <openssl/bio.h>

 const BIO_METHOD *BIO_f_null(void);

=head1 DESCRIPTION

BIO_f_null() returns the null filter BIO method. This is a filter BIO
that does nothing.

All requests to a null filter BIO are passed through to the next BIO in
the chain: this means that a BIO chain containing a null filter BIO
behaves just as though the BIO was not there.

=head1 NOTES

As may be apparent a null filter BIO is not particularly useful.

=head1 RETURN VALUES

BIO_f_null() returns the null filter BIO method.

=head1 COPYRIGHT

Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (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
L<https://www.openssl.org/source/license.html>.

=cut