AUDISP-REMOTE.CONF:
Section: System Administration Utilities (5)
Updated: June 2016
Page Index
NAME
audisp-remote.conf - the audisp-remote configuration file
DESCRIPTION
audisp-remote.conf is the file that controls the configuration of the audit remote logging subsystem. The options that are available are as follows:
- remote_server
-
This is a one word character string that is the remote server hostname or address that this plugin will send log information to. This can be the numeric address or a resolvable hostname.
- port
-
This option is an unsigned integer that indicates what port to connect to on the remote machine.
- local_port
-
This option is an unsigned integer that indicates what local port to
connect from on the local machine. If unspecified (the default) or
set to the word
any
then any available unpriviledged port is used. This is a security mechanism to prevent untrusted user space apps from injecting events into the audit daemon. You should set it to an unused port < 1024 to ensure that only privileged users can bind to that port. Then also set the tcp_client_ports in the aggregating auditd.conf file to match the ports that clients are sending from.
- transport
-
This parameter tells the remote logging app how to send events to the remote system. The only valid value right now is
tcp.
If set to
tcp,
the remote logging app will just make a normal clear text connection to the remote system. This is not used if kerberos is enabled.
- mode
-
This parameter tells the remote logging app what strategy to use getting records to the remote system. Valid values are
immediate, and forward .
If set to
immediate,
the remote logging app will attempt to send events immediately after getting them.
forward
means that it will store the events to disk and then attempt to send the records. If the connection cannot be made, it will queue records until it can connect to the remote system. The depth of the queue is controlled by the
queue_depth
option.
- queue_file
-
Path of a file used for the event queue if
mode
is set to forward. The default is /var/spool/audit/remote.log.
- queue_depth
-
This option is an unsigned integer that determines how many records can be buffered to disk or in memory before considering it to be a failure sending. This parameter affects the
forward
mode of the
mode
option and internal queueing for temporary network outtages. The default depth is 2048.
- format
-
This parameter tells the remote logging app what data format will be
used for the messages sent over the network. The default is
managed
which adds some overhead to ensure each message is properly handled on
the remote end, and to receive status messages from the remote server.
If
ascii
is given instead, each message is a simple ASCII text line with no
overhead at all. If
mode
is set to forward,
format
must be managed.
- network_retry_time
-
The time, in seconds, between retries when a network error is
detected. Note that this pause applies starting after the second
attempt, so as to avoid unneeded delays if a reconnect is sufficient
to fix the problem. The default is 1 second.
- max_tries_per_record
-
The maximum number of times an attempt is made to deliver each
message. The minimum value is one, as even a completely successful
delivery requires at least one try. If too many attempts are made,
the network_failure_action action is performed. The default is 3.
- max_time_per_record
-
The maximum amount of time, in seconds, spent attempting to deliver
each message. Note that both this and
max_tries_per_record
should be set, as each try may take a long time to time out. The
default value is 5 seconds. If too much time is used on a message,
the network_failure_action action is performed.
- heartbeat_timeout
-
This parameter determines how often in seconds the client should send a heartbeat event to the remote server. This is used to let both the client and server know that each end is alive and has not terminated in a way that it did not shutdown the connection uncleanly. This value must be coordinated with the server's
tcp_client_max_idle
setting. The default value is 0 which disables sending a heartbeat.
- network_failure_action
-
This parameter tells the system what action to take whenever there is an error
detected when sending audit events to the remote system. Valid values are
ignore, syslog, exec, warn_once, suspend, single, halt, and stop.
If set to
ignore,
the remote logging app does nothing. If an event was sent, its dequeued.
Syslog
means that it will issue a warning to syslog. If an event was sent, its dequeued. This is the default.
exec
/path-to-script will execute the script. You cannot pass parameters to the script. If an event was sent, its dequeued.
warn_once_continue
is like syslog execept that only one message is put in syslog until an event is successfully transferred.
warn_once
is like warn_once_continue execept that the event is not dequeued.
Suspend
will cause the remote logging app to stop sending records to the remote system. The logging app will still be alive. If an event was sent, it is not dequeued. The
single
option will cause the remote logging app to put the computer system in single user mode. If an event was sent, it is not dequeued. The
stop
option will cause the remote logging app to exit, but leave other plugins running. If an event was sent, it is not dequeued. The
halt
option will cause the remote logging app to shutdown the computer system. If an event was sent, it is not dequeued. The default is to stop.
- disk_low_action
-
Likewise, this parameter tells the system what action to take if the
remote end signals a disk low error. The default is ignore.
- disk_full_action
-
Likewise, this parameter tells the system what action to take if the
remote end signals a disk full error. The default is warn_once.
- disk_error_action
-
Likewise, this parameter tells the system what action to take if the
remote end signals a disk error. The default is warn_once.
- remote_ending_action
-
Likewise, this parameter tells the system what action to take if the
remote end signals a disk error. This action has one additional option,
reconnect
which tells the remote plugin to attempt to reconnect to the server upon receipt of the next audit record. If an event was being sent when something triggered this action, it is not dequeued. If it is unsuccessful in reconnecting, the audit record could be lost. The default is to reconnect.
- generic_error_action
-
Likewise, this parameter tells the system what action to take if the
remote end signals an error we don't recognize. The default is to log
it to syslog.
- generic_warning_action
-
Likewise, this parameter tells the system what action to take if the
remote end signals a warning we don't recognize. The default is to
log it to syslog.
- queue_error_action
-
Likewise, this parameter tells the system what action to take if there
is a problem working with a local record queue. The default is stop.
- overflow_action
-
This parameter tells the system what action to take if the
internal event queue overflows. Valid values are
ignore, syslog, suspend, single, and halt .
If set to
ignore,
the remote logging app does nothing.
Syslog
means that it will issue a warning to syslog. This is the default.
Suspend
will cause the remote logging app to stop sending records to the remote system. The logging app will still be alive. The
single
option will cause the remote logging app to put the computer system in single user mode. The
halt
option will cause the remote logging app to shutdown the computer system.
- enable_krb5
-
If set to "yes", Kerberos 5 will be used for authentication and
encryption. Default is "no". Note that encryption can only be used
with managed connections, not plain ASCII.
- krb5_principal
-
If specified, This is the expected principal for the server. The
client and server will use the specified principal to negotiate the
encryption. The format for the
krb5_principal
is like somename/hostname, see the auditd.conf man page for
details. If not specified, the krb5_client_name and remote_server values
are used.
- krb5_client_name
-
This specifies the name portion of the client's own principal. If
unspecified, the default is "auditd". The remainder of the principal
will consist of the host's fully qualified domain name and the default
Kerberos realm, like this:
auditd/host14.example.com@EXAMPLE.COM
(assuming you gave "auditd" as the krb_client_name). Note that the
client and server must have the same principal name and realm.
- krb5_key_file
-
Location of the key for this client's principal.
Note that the key file must be owned by root and mode 0400.
The default is
/etc/audisp/audisp-remote.key
NOTES
Specifying a local port may make it difficult to restart the audit
subsystem due to the previous connection being in a TIME_WAIT state,
if you're reconnecting to and from the same hosts and ports as before.
The network failure logic works as follows: The first attempt to
deliver normally "just works". If it doesn't, a second attempt is
immediately made, perhaps after reconnecting to the server. If
the second attempt also fails,
audispd-remote
pauses for the configured time and tries again. It continues to pause
and retry until either too many attempts have been made or the allowed
time expires. Note that these times govern the maximum amount of time
the remote server is allowed in order to reboot, if you want to
maintain logging across a reboot.
SEE ALSO
audispd(8),
audisp-remote(8),
auditd.conf(5).
AUTHOR
Steve Grubb