TCBCK(ADM) UNIX System V
Name
tcbck, smmck, authckrc - trusted computing base checker
Syntax
tcbck
Description
tcbck checks the files in the trusted computing base for
files that were caught in the process of being updated when
the system went down, and for files that have been removed.
tcbck is invoked by the scripts /etc/smmck during system
maintenance mode, and by /etc/authckrc when the system
enters multi-user mode. The check proceeds as follows:
1. /etc/smmck runs tcbck to clean up any database files
that were left in an interim state while being updated
(files are created with -o (old) and -t (new) suffixes,
respectively). When this process is interrupted, -o
and -t files are left and must be reconciled before the
system will function properly. tcbck checks the
/etc/auth/system, /etc/auth/subsystems and
/tcb/files/auth/* directories. If there are multiple
versions of a file, the extra files are removed. When
a -t file is found, the following is displayed:
/etc/tcbck: file file missing, saved file-t as file
This message is repeated for all files found in that
state in the specified directories.
2. Next tcbck removes /etc/auth/system/pw_id_map and
/etc/auth/system/gr_id_map because the modification
times of these files are compared with that of
/etc/passwd and /etc/group and problems can occur when
th system clock is reset.
3. tcbck checks that key system files are present and that
they are not of zero length. If a file is missing (or
zero length) then a message similar to this is
displayed:
/etc/tcbck: file file is missing or zero length
This process is repeated for each of the following
files:
/etc/auth/system/default†
/etc/auth/system/files
/etc/auth/system/devassign
/etc/auth/system/ttys
/etc/auth/system/authorize†
/tcb/files/auth/r/root†
/etc/group
/etc/passwd†
When this process is complete, if any files were missing or
-t files were substituted for real files, the following
message is displayed:
/etc/smmck: restore missing files from backup or distribution.
4. If critical database files have been removed or corrupted
(files marked with a dagger (†) in the previous file list
are considered critical) then the system enters maintenance
mode automatically without asking for the root password. If
no critical database files were lost, the system prompts for
maintenance mode or normal operation.
5. After the system goes to init level 2, /etc/authckrc
reinvokes tcbck to confirm that the files reported missing
previously have been restored: Any missing files are
listed, followed by this message:
/etc/authckrc: Log in on the OVERRIDE tty and restore
the missing files from a backup or the distribution disks.
Missing files will have to be replaced when the system comes
up multi-user.
6. Finally authckrc prompts for checking the protected
subsystem databases. If the response is yes, the
authck(ADM) program is run.
Value Added
tcbck is an extension of AT&T System V provided by the Santa
Cruz Operation.
(printed 4/27/90) TCBCK(ADM)