uses URL extensions to set socket permissions other than default

URL Syntax:

ldapi://[<path>[/????[!]x-mod=<mod>]]

where <path> is the URL-encoded path of the socket (i.e. use %2F instead
of '/' for UNIX filenames!) and <mod> is 3*[w|-] (all we need is write
permission to the socket, read/execute permissions are ignored; however,
they're set when opening the listener).  The critical flag (the optional
'!' if not used ignores the result of the chmod() operation.