NAME¶
auditd - The Linux Audit daemon
SYNOPSIS¶
auditd
[
-f] [
-l] [
-n] [
-s disable|enable|nochange]
DESCRIPTION¶
auditd is the userspace component to the Linux Auditing System. It's
responsible for writing audit records to the disk. Viewing the logs is done
with the
ausearch or
aureport utilities. Configuring the audit
rules is done with the
auditctl utility. During startup, the rules in
/etc/audit/audit.rules are read by
auditctl and loaded into the
kernel. Alterately, there is also an
augenrules program that reads
rules located in
/etc/audit/rules.d/ and compiles them into an
audit.rules file. The audit daemon itself has some configuration options that
the admin may wish to customize. They are found in the
auditd.conf
file.
OPTIONS¶
- -f
- leave the audit daemon in the foreground for debugging. Messages also go
to stderr rather than the audit log.
- -l
- allow the audit daemon to follow symlinks for config files.
- -n
- no fork. This is useful for running off of inittab or systemd.
- -s=ENABLE_STATE
- specify when starting if auditd should change the current value for the
kernel enabled flag. Valid values for ENABLE_STATE are
"disable", "enable" or "nochange". The
default is to enable (and disable when auditd terminates). The value of
the enabled flag may be changed during the lifetime of auditd using
'auditctl -e'.
SIGNALS¶
- SIGHUP
- causes auditd to reconfigure. This means that auditd re-reads the
configuration file. If there are no syntax errors, it will proceed to
implement the requested changes. If the reconfigure is successful, a
DAEMON_CONFIG event is recorded in the logs. If not successful, error
handling is controlled by space_left_action, admin_space_left_action,
disk_full_action, and disk_error_action parameters in auditd.conf.
- SIGTERM
- caused auditd to discontinue processing audit events, write a shutdown
audit event, and exit.
- SIGUSR1
- causes auditd to immediately rotate the logs. It will consult the
max_log_size_action to see if it should keep the logs or not.
- SIGUSR2
- causes auditd to attempt to resume logging. This is usually needed after
logging has been suspended.
FILES¶
/etc/audit/auditd.conf - configuration file for audit daemon
/etc/audit/audit.rules - audit rules to be loaded at startup
/etc/audit/rules.d/ - directory holding individual sets of rules to be
compiled into one file by augenrules.
NOTES¶
A boot param of audit=1 should be added to ensure that all processes that run
before the audit daemon starts is marked as auditable by the kernel. Not doing
that will make a few processes impossible to properly audit.
The audit daemon can receive audit events from other audit daemons via the
audisp-remote audispd plugin. The audit daemon may be linked with tcp_wrappers
to control which machines can connect. If this is the case, you can add an
entry to hosts.allow and deny.
SEE ALSO¶
auditd.conf(5),
audispd(8),
ausearch(8),
aureport(8),
auditctl(8),
augenrules(8),
audit.rules(7).
AUTHOR¶
Steve Grubb