NAME
authbind-helper - helper program to bind sockets to privileged ports without root
SYNOPSIS
I /usr/lib/authbind/helper addr-hex port-hex < socket
DESCRIPTION
helper
is the program used by
R libauthbind ,
which is in turn used by
authbind
to allow programs which do not or should not run as root to bind to
low-numbered ports in a controlled way. See
authbind(1).
It may also be used standalone, i.e. without assistance from
R authbind .
Its standard input should be a TCP/IP socket, and it should be passed
two arguments.
The arguments are the address and port number, respectively, to which
the caller desires that the socket be bound. They should be hex
strings,
without
leading
R 0x ,
of exactly the right length (8 and 4 digits, respectively), being
a pairs of hex digits for each byte in the address or port number when
expressed in network byte order.
helper
will not bind to ports 512 and onwards, because programs like
rshd
expect these to be used for outgoing connections, so allowing a user
to bind to one of these would open up security hole(s).
EXIT STATUS
helper
will exit with code 0 on success.
If possible,
helper
will return an appropriate
errno
value as its exit status. If this is not possible it may exit with
status 255 or with an exit status corresponding to
ENOSYS
(Function not implemented).
ACCESS CONTROL
See
authbind(1)
for details of the access control regime implemented by
R helper .
SEE ALSO
AUTHOR
authbind
and this manpage were written by Ian Jackson. They are
Copyright (C)1998
by him and released under the GNU General Public Licence; there is NO
WARRANTY. See
/usr/doc/authbind/copyright
and
/usr/doc/copyright/GPL
for details.
