auditmask(8) System Manager's Manual auditmask(8)
NAME
auditmask - Gets or sets audit masks
SYNOPSIS
/usr/sbin/auditmask [ flags ] [ event[:succeed:fail]] [-e,E file [args... ]] [< event_list]
FLAGS
Sets the audit mask for all processes that have the specified audit ID (audit_id). By specifying the audit ID of a user, all processes
with the specified audit ID are audited. The event list specified on the command line becomes the audit mask for the target processes.
Note that the new events are combined with the current events for the target process. Executes auditmask on each active member of the
cluster. Any files specified must be visable to all members in the cluster. Process-specific commands are not supported across the clus-
ter. Entering auditmask -cluster prints out each cluster member's audit mask.
The following auditmask options are supported with the -cluster option and work as follows: Has valid meaning only for a cluster member
that the user is currently logged into. Not valid if -p is used. With a specified process -f is not supported with -cluster. Without a
specified process, -f is supported. Supported. With a specified procces -n is not supported with -cluster. Without a specified procces
-n works as usual across each cluster member. Works as usual across each cluster member.
The following auditmask options are not supported with the -cluster option: Sets the value of the audit control flags for the target audit
processes. The -c flag can be used only in conjunction with the -a, -e, -E, or -p flags. The audit control flag strings are as follows: An
audit record is generated if either the system audit mask or the process audit mask indicates such an event should be audited. An audit
record is generated if both the system audit mask and the process audit mask indicate such an event should be audited. No audit records
are generated for the current process. An audit record gets generated if the process audit mask indicates such an event should be audited.
Turns off or on all system call auditing for the selected process (or group of processes if based on login user). Include the habitat
audit events as described in the /etc/sec/audit_events file. Executes the file and audits all system calls and trusted events. The args
parameters are the arguments associated with the program file. This option is useful for debugging. Executes the file and audits under a
specified audit mask. The args parameters are the arguments associated with the program file. For example, auditmask open -e test_prog foo
If a process is specified, sets that process' audit mask to all events; otherwise, sets the system audit mask to all events. Displays a
brief help message. If a process is specified, clears that process' audit mask; otherwise, clears the system audit mask. When one or more
events are provided, sets the audit mask for a single process specified by pid and events. The event list specified on the command line
modifies the settings for those events in the current audit mask of the specified process. If only -p pid is specified, the events being
audited for the specified pid and the audcntl flag are returned. The -p option is used to check a suspicious process in real time. Query
status of file filename for object selection/deselection. Query status of files in filelist relevant to object selection/deselection.
Sets the audit style characteristics of the audit subsystem as follows: Enables the auditing of the argument list to an execv or execve
system call. Enables the auditing of the environment strings to an execv or execve system call. Enables recording the command name in
each audit record. The command name is the same name as that used in the accounting records. This is the last component of the invoked
pathname, and is restricted to a maximum of 16 characters. Enables the auditing of the user name in failed login attempts when the user
name is not recognized. (If the account name for a failed access attempt is recognized, an entry is always generated in the audit log.)
Enable object selection mode. Specifying -c obj_sel or -c obj_sel:1 enables the object selection mode. Specifying -c obj_sel:0 disables
the object selection mode. The object selection mode provides the ability to specify a set of files for which selected events get audited,
while those same events on other files do not get audited. In this mode, audit records get generated only when an event is selected and
either that event is acting on a selected file or not acting on any file. The result is that it is now possible, for example, to audit
open's of /etc/passwd and /.rhosts while not auditing open's of /tmp/xxxx. See the -x and -X options, and the Security manual. Enable
object deselection mode. Specifying -c obj_desel or -c obj_desel:1 enables the deselection mode. Specifying -c obj_desel:0 disables the
deselection mode. The file deselection mode provides the ability to specify a set of files for which specific selected events do not get
audited, while those same events on other files do get audited. The events which may be deselected are data access operations (no data
modifications). The set of events which get deselected is:
open close link access stat lstat dup revoke readlink fstat dup2 getdirentries read lseek File open's
for write or truncate access, however, do not get deselected. In this mode, audit records get generated for selected events, unless all
files operated on by that system call are deselected and the operation is a data access. So, if you are auditing stat and unlink, and the
file foo is deselected, then a stat of foo would not be audited, but an unlink of foo would be audited (the unlink is not a "data access"
operation). The result is that it is now possible, for example, to not audit accesses to /usr/shlib/libc.so, but still audit open's of
/etc/passwd. See the -y and -Y options, and the Security manual. Enable or disable selection on filename. No : or the presence of a :1
on the end of the argument enables the action; a :0 disables the action. Enable or disable selection on the files in the filelist. No :
or the presence of a :1 on the end of the argument enables the action; a :0 disables the action. Enable or disable deselection on file-
name. No : or the presence of a :1 on the end of the argument enables the action; a :0 disables the action. Enable or disable deselection
on the files in the filelist. No : or the presence of a :1 on the end of the argument enables the action; a :0 disables the action.
DESCRIPTION
The auditmask command is used to: Get or set the system audit mask and the audit style flag Get or set a process' audit mask and its audit
control flag Execute a process under a specified audit mask Select or deselect filesystem objects
The system audit mask contains system calls (default list is in /etc/sec/audit_events), trusted events (defined in audit.h), and site-
defined events (/etc/sec/site_events). The system audit mask is set during the setup of the audit subsystem using the auditconfig script.
The system audit mask can be changed at any time using the auditmask command.
Under enhanced security, when a user logs in to the system, the authentication databases (/var/tcb/files/auth.db and
/var/tcb/files/auth.db) are read and the login process' audit characteristics are set according to the u_auditmask and u_auditcntl entries.
This audit mask and audit control flag are inherited by all spawned processes.
Setting the audit control flag of a process automatically resets a previous setting of AUDIT_SYSCALL_OFF for that process.
Getting the System Audit Mask
The auditmask command with no arguments displays the system calls, trusted events, and site events currently being audited for the system,
and indicates whether they are being audited under successful or failed occurrences or both. The format used for the display is acceptable
as input to subsequent auditmask commands.
Setting the System Audit Mask
The auditmask command with event arguments sets the system call, trusted event, or site event audit masks for the system audit mask. This
is a cumulative operation, so it is possible to turn on or off audit for one set of events, then turn on or off audit for a second set of
events without changing the first set of events (except for the intersection between the two sets). Command line arguments to auditmask
can include one or more events, each with an optional field :succeed:fail, where succeed is either 0 to specify no auditing of successful
occurrences of event or 1 to specify auditing of successful occurrences of event; and fail is either 0 to specify no auditing of failed
occurrences of event or 1 to specify auditing of failed occurrences of event. The event is one of the following: A system call name A
trusted event name (see audit.h) A site-defined name in /etc/sec/site_events An alias defined in /etc/sec/event_aliases
The auditmask command will also accept redirected input, which can be the output of a previously issued auditmask command. This is a file
containing lines in the following format:
event [succeed] [fail]
If the keyword succeed is present, successful occurrences of that event will be audited; if the keyword fail is present, failed occurrences
of that event will be audited; if both are present, successful and failed occurrences will be audited; if neither keyword is present, that
event will not be audited.
The auditmask command with the -s option is used to set the audit style characteristics of the audit subsystem. See the description of the
-s option.
Getting and Setting Process' Auditmask
The audit characteristics for a process are made up of the process auditmask and the audit control flag. The auditmask command can be used
to set or get the audit characteristics for a specified process. If no audit characteristics are specified, auditmask gets the process'
auditmask and control flag; if any audit characteristics are specified, auditmask sets the process' auditmask and/or the audit control
flag.
Processes are specified as follows: A single process using the -p option A family of processes using the -a option A new process using the
-e or -E option
Site-defined events and habitat system calls can be set only for the system, as opposed to the processes. See the habitat_usr selection
under the -c control_flag flag.
A program can be executed with a specified auditmask using the -e or -E options. This can be used to learn more about the program's behav-
ior. The -e and -E options set the process audit control flag to AUDIT_USR (unless explicitly set otherwise).
Using Object Selection and Deselection
Object selection and deselection modes provide another preselection mechanism designed to help administrators audit specifically those
operations of interest to them.
Some events, such as mount and reboot, are operations affecting system state; other events, such as open and unlink, are operations which
affect specific files. While all reboot attempts might be security relevant, all file open's might not be (based on the site security
model). The file object selection/deselection mechanism provides a further level of granularity for events which operate on files.
This mechanism can be run in either file selection (audstyle obj_sel) or file deselection (audstyle obj_desel) mode.
Note that processes with a flag of AUDIT_USR do not have their auditing reduced through the selection/deselection mechanism.
Cluster Audit Masks
Each member of a cluster runs with its own auditmask. To simplify keeping the masks identical, use the -cluster option.
EXAMPLES
The command line in the following example returns the auditmask and audit control flag for process 999:
# auditmask -p 999
The command line in the following example executes the my_prog program with the open system call added to its auditmask and no change to
its audit control flag:
# auditmask open -e my_prog
The command line in the following example executes the vi command on the /etc/motd file with its auditmask set to audit all system calls
and all trusted events, and its audit control flag set to OR:
# auditmask -c or -E vi /etc/motd
RELATED INFORMATION
Commands: auditconfig(8)
Functions: audcntl(2)
Security delim off
auditmask(8)