authbind-helper - helper program to bind sockets to privileged ports without
root
/usr/lib/authbind/helper addr4-hex port-hex
<socket
/usr/lib/authbind/helper addr6-hex port-hex 6
<socket
helper is the program used by
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
authbind.
Its standard input should be a TCP/IP socket, and it should be passed two or
three arguments.
The arguments are the address and port number, respectively, to which the caller
desires that the socket be bound, and the address family (ommitted for IPv4;
the fixed string
6 for IPv6).
addr4-hex and
port-hex
should be hex strings,
without leading
0x, of exactly the right
length (8 and 4 digits, respectively), being a pair of hex digits for each
byte in the address or port number when expressed in host byte order. For
example, the port argument is the result of something like
sprintf(arg,
"%04X", sin.sin_port).
addr6-hex should be a
string of 32 hex digits, being a pair for each byte in the address, in network
byte order.
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).
See
authbind(1) for details of the access control regime implemented by
helper.
authbind(1),
bind(2)
authbind and this manpage were written by Ian Jackson. They are Copyright
(C)1998,2012 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.