=pod

=head1 NAME

BIO_f_null - null filter

=head1 SYNOPSIS

 #include <openssl/bio.h>

 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 SEE ALSO

TBA