realhostname_sa
- convert a
Vt struct sockaddr
to the real host name
LIBRARY
Lb libutil
SYNOPSIS
#include <sys/types.h>
#include <netinet/in.h>
#include <libutil.h> int
realhostname_sa (char *host size_t hsize struct sockaddr *addr int addrlen);
DESCRIPTION
The function
realhostname_sa ();
converts
addr
to the corresponding host name.
This is done by resolving
addr
to a host name and then ensuring that the host name resolves
back to
addr
host
must point to a buffer of at least
hsize
bytes, and will always be written to by this function.
If the name resolution does not work both ways or if the host name is longer
than
hsize
bytes,
getnameinfo(3)
with NI_NUMERICHOST specified, is used to convert
addr
to an ASCII form.
If the string written to
host
is
hsize
bytes long,
host
will not be NUL terminated.
RETURN VALUES
The
realhostname_sa ();
function will return one of the following constants which are defined in
In libutil.h :
HOSTNAME_FOUND
A valid host name was found.
HOSTNAME_INCORRECTNAME
A host name was found, but it did not resolve back to the passed
iphost
now contains the numeric value of
ip
HOSTNAME_INVALIDADDR
ip
could not be resolved.
host
now contains the numeric value of
ip
HOSTNAME_INVALIDNAME
A host name was found, but it could not be resolved back to any ip number.
host
now contains the numeric value of
ip
