=pod

=head1 NAME

BIO_ADDR, BIO_ADDR_new, BIO_ADDR_clear, BIO_ADDR_free, BIO_ADDR_rawmake,
BIO_ADDR_family, BIO_ADDR_rawaddress, BIO_ADDR_rawport,
BIO_ADDR_hostname_string, BIO_ADDR_service_string,
BIO_ADDR_path_string - BIO_ADDR routines

=head1 SYNOPSIS

 #include <sys/types.h>
 #include <openssl/bio.h>

 typedef union bio_addr_st BIO_ADDR;

 BIO_ADDR *BIO_ADDR_new(void);
 void BIO_ADDR_free(BIO_ADDR *);
 void BIO_ADDR_clear(BIO_ADDR *ap);
 int BIO_ADDR_rawmake(BIO_ADDR *ap, int family,
                      const void *where, size_t wherelen, unsigned short port);
 int BIO_ADDR_family(const BIO_ADDR *ap);
 int BIO_ADDR_rawaddress(const BIO_ADDR *ap, void *p, size_t *l);
 unsigned short BIO_ADDR_rawport(const BIO_ADDR *ap);
 char *BIO_ADDR_hostname_string(const BIO_ADDR *ap, int numeric);
 char *BIO_ADDR_service_string(const BIO_ADDR *ap, int numeric);
 char *BIO_ADDR_path_string(const BIO_ADDR *ap);

=head1 DESCRIPTION

The B<BIO_ADDR> type is a wrapper around all types of socket
addresses that OpenSSL deals with, currently transparently
supporting AF_INET, AF_INET6 and AF_UNIX according to what's
available on the platform at hand.

BIO_ADDR_new() creates a new unfilled B<BIO_ADDR>, to be used
with routines that will fill it with information, such as
BIO_accept_ex().

BIO_ADDR_free() frees a B<BIO_ADDR> created with BIO_ADDR_new().

BIO_ADDR_clear() clears any data held within the provided B<BIO_ADDR> and sets
it back to an uninitialised state.

BIO_ADDR_rawmake() takes a protocol B<family>, a byte array of
size B<wherelen> with an address in network byte order pointed at
by B<where> and a port number in network byte order in B<port> (except
for the B<AF_UNIX> protocol family, where B<port> is meaningless and
therefore ignored) and populates the given B<BIO_ADDR> with them.
In case this creates a B<AF_UNIX> B<BIO_ADDR>, B<wherelen> is expected
to be the length of the path string (not including the terminating
NUL, such as the result of a call to strlen()).
I<Read on about the addresses in L</RAW ADDRESSES> below>.

BIO_ADDR_family() returns the protocol family of the given
B<BIO_ADDR>.  The possible non-error results are one of the
constants AF_INET, AF_INET6 and AF_UNIX. It will also return AF_UNSPEC if the
BIO_ADDR has not been initialised.

BIO_ADDR_rawaddress() will write the raw address of the given
B<BIO_ADDR> in the area pointed at by B<p> if B<p> is non-NULL,
and will set B<*l> to be the amount of bytes the raw address
takes up if B<l> is non-NULL.
A technique to only find out the size of the address is a call
with B<p> set to B<NULL>.  The raw address will be in network byte
order, most significant byte first.
In case this is a B<AF_UNIX> B<BIO_ADDR>, B<l> gets the length of the
path string (not including the terminating NUL, such as the result of
a call to strlen()).
I<Read on about the addresses in L</RAW ADDRESSES> below>.

BIO_ADDR_rawport() returns the raw port of the given B<BIO_ADDR>.
The raw port will be in network byte order.

BIO_ADDR_hostname_string() returns a character string with the
hostname of the given B<BIO_ADDR>.  If B<numeric> is 1, the string
will contain the numerical form of the address.  This only works for
B<BIO_ADDR> of the protocol families AF_INET and AF_INET6.  The
returned string has been allocated on the heap and must be freed
with OPENSSL_free().

BIO_ADDR_service_string() returns a character string with the
service name of the port of the given B<BIO_ADDR>.  If B<numeric>
is 1, the string will contain the port number.  This only works
for B<BIO_ADDR> of the protocol families AF_INET and AF_INET6.  The
returned string has been allocated on the heap and must be freed
with OPENSSL_free().

BIO_ADDR_path_string() returns a character string with the path
of the given B<BIO_ADDR>.  This only works for B<BIO_ADDR> of the
protocol family AF_UNIX.  The returned string has been allocated
on the heap and must be freed with OPENSSL_free().

=head1 RAW ADDRESSES

Both BIO_ADDR_rawmake() and BIO_ADDR_rawaddress() take a pointer to a
network byte order address of a specific site.  Internally, those are
treated as a pointer to B<struct in_addr> (for B<AF_INET>), B<struct
in6_addr> (for B<AF_INET6>) or B<char *> (for B<AF_UNIX>), all
depending on the protocol family the address is for.

=head1 RETURN VALUES

The string producing functions BIO_ADDR_hostname_string(),
BIO_ADDR_service_string() and BIO_ADDR_path_string() will
return B<NULL> on error and leave an error indication on the
OpenSSL error stack.

All other functions described here return 0 or B<NULL> when the
information they should return isn't available.

=head1 SEE ALSO

L<BIO_connect(3)>, L<BIO_s_connect(3)>

=head1 COPYRIGHT

Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (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
