anyaddr.3

This a good VPN source

.TH IPSEC_ANYADDR 3 "8 Sept 2000"
.\" RCSID $Id: anyaddr.3,v 1.4 2004/04/09 18:00:35 mcr Exp $
.SH NAME
ipsec anyaddr \- get "any" address
.br
ipsec isanyaddr \- test address for equality to "any" address
.br
ipsec unspecaddr \- get "unspecified" address
.br
ipsec isunspecaddr \- test address for equality to "unspecified" address
.br
ipsec loopbackaddr \- get loopback address
.br
ipsec isloopbackaddr \- test address for equality to loopback address
.SH SYNOPSIS
.B "#include <freeswan.h>
.sp
.B "const char *anyaddr(int af, ip_address *dst);"
.br
.B "int isanyaddr(const ip_address *src);"
.br
.B "const char *unspecaddr(int af, ip_address *dst);"
.br
.B "int isunspecaddr(const ip_address *src);"
.br
.B "const char *loopbackaddr(int af, ip_address *dst);"
.br
.B "int isloopbackaddr(const ip_address *src);"
.SH DESCRIPTION
These functions fill in, and test for, special values of the
.I ip_address
type.
.PP
.I Anyaddr
fills in the destination
.I *dst
with the ``any'' address of address family
.IR af
(normally
.B AF_INET
or
.BR AF_INET6 ).
The IPv4 ``any'' address is the one embodied in the old
.B INADDR_ANY
macro.
.PP
.I Isanyaddr
returns
.B 1
if the
.I src
address equals the ``any'' address,
and
.B 0
otherwise.
.PP
Similarly,
.I unspecaddr
supplies, and
.I isunspecaddr
tests for,
the ``unspecified'' address,
which may be the same as the ``any'' address.
.PP
Similarly,
.I loopbackaddr
supplies, and
.I islookbackaddr
tests for,
the loopback address.
.PP
.IR Anyaddr ,
.IR unspecaddr ,
and
.I loopbackaddr
return
.B NULL
for success and
a pointer to a string-literal error message for failure;
see DIAGNOSTICS.
.SH SEE ALSO
inet(3), ipsec_addrtot(3), ipsec_sameaddr(3)
.SH DIAGNOSTICS
Fatal errors in the address-supplying functions are:
unknown address family.
.SH HISTORY
Written for the FreeS/WAN project by Henry Spencer.