The routine
link_addr ();
interprets character strings representing
link-level addresses, returning binary information suitable
for use in system calls.
The routine
link_ntoa ();
takes
a link-level
address and returns an
ASCII
string representing some of the information present,
including the link level address itself, and the interface name
or number, if present.
This facility is experimental and is
still subject to change.
For
link_addr (,);
the string
Fa addr
may contain
an optional network interface identifier of the form
``name unit-number''
suitable for the first argument to
ifconfig(8),
followed in all cases by a colon and
an interface address in the form of
groups of hexadecimal digits
separated by periods.
Each group represents a byte of address;
address bytes are filled left to right from
low order bytes through high order bytes.
Thus
le0:8.0.9.13.d.30
represents an ethernet address
to be transmitted on the first Lance ethernet interface.
RETURN VALUES
The
link_ntoa ();
function
always returns a null terminated string.
The
link_addr ();
function
has no return value.
(See
Sx BUGS . )
The
link_addr ();
and
link_ntoa ();
functions appeared in
BSD 4.3 Reno
BUGS
The returned values for link_ntoa
reside in a static memory area.
The function
link_addr ();
should diagnose improperly formed input, and there should be an unambiguous
way to recognize this.
If the
sdl_len
field of the link socket address
Fa sdl
is 0,
link_ntoa ();
will not insert a colon before the interface address bytes.
If this translated address is given to
link_addr ();
without inserting an initial colon,
the latter will not interpret it correctly.