TOPS-10 Monitor Calls Manual Volume 2 AA-K039D ... - Trailing-Edge

APPENDIX B
FILE DAEMON
The File Daemon provides extended file protection. The File Daemon
described in this appendix is a prototype that you may use to help you
in understanding the monitor support for this feature. The File
Daemon is supplied only to serve as a prototype for the File Daemon
you may desire at your installation.
Each installation will have varying types of accounting and file
security measures. Therefore, each installation's File Daemon may be
written to account for these differences and varying requirements.
The DIGITAL-supplied, prototype File Daemon supports access lists and
access logging that is performed on a user's or a system
administrator's request.
B.l USER INTERFACE
The File Daemon allows any user to specify who can and who cannot
access his files. Each user may create a file named ACCESS.USR (which
is described in Section C.3). This file optionally lists the names of
some or all of that user's files and specifies, on an individual file
basis, the users who can and cannot access those files. Under
specific conditions, the File Daemon examines the user's ACCESS.USR
file and may record information, in a separate file called ACCESS.LOG,
regarding specific access requests to the listed files. Note that
ACCESS.USR can be created only by the owner of the particular
directory or by a job logged in under [1,2].
B.2 THE FILE DAEMON
The monitor calls the File Daemon (only if the monitor feature
switch F%FDAE = -1) each time that someone tries to·access a file
has a 4, 5, 6, or 7 protection code in the owner's protection
field and the access fails due to a file protection error or due
directory protection error.
test
that
code
to a
For example, if you protect a file against a specific user and that
user attempts to access your file (with a LOOKUP, ENTER, RENAME, or
FILOP. monitor call), the monitor suspends the execution of the
accessing user's program and it sends a message to the File Daemon.
This message includes the type of access the user is attempting and
that user's project-programmer number. The monitor gives control to
the File Daemon, which looks for your file called ACCESS.USR.
ACCESS.USR must be on the same file structure and in the same
directory area as the file being accessed.
B-1