2006-06-05 15:26:09 +00:00
|
|
|
.\" Copyright (c) 2006 Robert N. M. Watson
|
|
|
|
.\" All rights reserved.
|
|
|
|
.\"
|
|
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
|
|
.\" modification, are permitted provided that the following conditions
|
|
|
|
.\" are met:
|
|
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
|
|
.\"
|
|
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
|
|
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
|
|
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
|
|
.\" SUCH DAMAGE.
|
|
|
|
.\"
|
|
|
|
.\" $FreeBSD$
|
|
|
|
.\"
|
|
|
|
.Dd May 5, 2006
|
|
|
|
.Os
|
|
|
|
.Dt AUDITPIPE 4
|
|
|
|
.Sh NAME
|
|
|
|
.Nm auditpipe
|
2006-09-30 15:14:49 +00:00
|
|
|
.Nd "pseudo-device for live audit event tracking"
|
2006-06-05 15:26:09 +00:00
|
|
|
.Sh SYNOPSIS
|
|
|
|
.Cd "options AUDIT"
|
|
|
|
.Sh DESCRIPTION
|
|
|
|
While audit trail files
|
|
|
|
generated with
|
|
|
|
.Xr audit 4
|
|
|
|
and maintained by
|
|
|
|
.Xr auditd 8
|
|
|
|
provide a reliable long-term store for audit log information, current log
|
|
|
|
files are owned by the audit daemon until terminated making them somewhat
|
2006-06-05 16:31:57 +00:00
|
|
|
unwieldy for live monitoring applications such as host-based intrusion
|
2006-06-05 15:26:09 +00:00
|
|
|
detection.
|
|
|
|
For example, the log may be cycled and new records written to a new file
|
|
|
|
without notice to applications that may be accessing the file.
|
|
|
|
.Pp
|
|
|
|
The audit facility provides an audit pipe facility for applications requiring
|
|
|
|
direct access to live BSM audit data for the purposes of real-time
|
|
|
|
monitoring.
|
|
|
|
Audit pipes are available via a clonable special device,
|
|
|
|
.Pa /dev/auditpipe ,
|
2006-09-30 15:14:49 +00:00
|
|
|
subject to the permissions on the device node, and provide a
|
2006-06-05 15:26:09 +00:00
|
|
|
.Qq tee
|
|
|
|
of the audit event stream.
|
|
|
|
As the device is clonable, more than one instance of the device may be opened
|
|
|
|
at a time; each device instance will provide independent access to all
|
|
|
|
records.
|
|
|
|
.Pp
|
|
|
|
The audit pipe device provides discrete BSM audit records; if the read buffer
|
|
|
|
passed by the application is too small to hold the next record in the
|
|
|
|
sequence, it will be dropped.
|
|
|
|
Unlike audit data written to the audit trail, the reliability of record
|
|
|
|
delivery is not guaranteed.
|
|
|
|
In particular, when an audit pipe queue fills, records will be dropped.
|
|
|
|
Audit pipe devices are blocking by default, but support non-blocking I/O,
|
2006-09-30 15:14:49 +00:00
|
|
|
asynchronous I/O using
|
|
|
|
.Dv SIGIO ,
|
|
|
|
and polled operation via
|
2006-06-05 15:26:09 +00:00
|
|
|
.Xr select 2
|
|
|
|
and
|
|
|
|
.Xr poll 2 .
|
|
|
|
.Pp
|
|
|
|
Applications may choose to track the global audit trail, or configure local
|
|
|
|
preselection parameters independent of the global audit trail parameters.
|
|
|
|
.Ss Audit Pipe Queue Ioctls
|
|
|
|
The following ioctls retrieve and set various audit pipe record queue
|
|
|
|
properties:
|
2006-09-30 15:14:49 +00:00
|
|
|
.Bl -tag -width ".Dv AUDITPIPE_GET_MAXAUDITDATA"
|
|
|
|
.It Dv AUDITPIPE_GET_QLEN
|
2006-06-05 15:26:09 +00:00
|
|
|
Query the current number of records available for reading on the pipe.
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_GET_QLIMIT
|
2006-06-05 15:26:09 +00:00
|
|
|
Retrieve the current maximum number of records that may be queued for reading
|
|
|
|
on the pipe.
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_SET_QLIMIT
|
2006-06-05 15:26:09 +00:00
|
|
|
Set the current maximum number of records that may be queued for reading on
|
|
|
|
the pipe.
|
|
|
|
The new limit must fall between the queue limit minimum and queue limit
|
|
|
|
maximum queryable using the following two ioctls.
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_GET_QLIMIT_MIN
|
2006-06-05 15:26:09 +00:00
|
|
|
Query the lowest possible maximum number of records that may be queued for
|
|
|
|
reading on the pipe.
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_GET_QLIMIT_MAX
|
2006-06-05 15:26:09 +00:00
|
|
|
Query the highest possible maximum number of records that may be queued for
|
|
|
|
reading on the pipe.
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_FLUSH
|
2006-06-05 15:26:09 +00:00
|
|
|
Flush all outstanding records on the audit pipe; useful after setting initial
|
|
|
|
preselection properties to delete records queued during the configuration
|
|
|
|
process which may not match the interests of the user process.
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_GET_MAXAUDITDATA
|
2006-08-26 17:59:31 +00:00
|
|
|
Query the maximum size of an audit record, which is a useful minimum size for
|
|
|
|
a user space buffer intended to hold audit records read from the audit pipe.
|
2006-06-05 15:26:09 +00:00
|
|
|
.El
|
|
|
|
.Ss Audit Pipe Preselection Mode Ioctls
|
|
|
|
By default, the audit pipe facility configures pipes to present records
|
|
|
|
matched by the system-wide audit trail, configured by
|
|
|
|
.Xr auditd 8 .
|
|
|
|
However, the preselection mechanism for audit pipes can be configured using
|
|
|
|
alternative criteria, including pipe-local flags and naflags settings, as
|
|
|
|
well as auid-specific selection masks.
|
|
|
|
This allows applications to track events not captured in the global audit
|
|
|
|
trail, as well as limit records presented to those of specific interest to
|
|
|
|
the application.
|
|
|
|
.Pp
|
|
|
|
The following ioctls configure the preselection mode on an audit pipe:
|
2006-09-30 15:14:49 +00:00
|
|
|
.Bl -tag -width ".Dv AUDITPIPE_GET_PRESELECT_MODE"
|
|
|
|
.It Dv AUDITPIPE_GET_PRESELECT_MODE
|
2006-06-05 15:26:09 +00:00
|
|
|
Return the current preselect mode on the audit pipe.
|
|
|
|
The ioctl argument should be of type
|
|
|
|
.Vt int .
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_SET_PRESELECT_MODE
|
2006-06-05 15:26:09 +00:00
|
|
|
Set the current preselection mode on the audit pipe.
|
|
|
|
The ioctl argument should be of type
|
|
|
|
.Vt int .
|
|
|
|
.El
|
|
|
|
.Pp
|
|
|
|
Possible preselection mode values are:
|
2006-09-30 15:14:49 +00:00
|
|
|
.Bl -tag -width ".Dv AUDITPIPE_PRESELECT_MODE_TRAIL"
|
|
|
|
.It Dv AUDITPIPE_PRESELECT_MODE_TRAIL
|
2006-06-05 15:26:09 +00:00
|
|
|
Use the global audit trail preselection parameters to select records for the
|
|
|
|
audit pipe.
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_PRESELECT_MODE_LOCAL
|
2006-06-05 15:26:09 +00:00
|
|
|
Use local audit pipe preselection; this model is similar to the global audit
|
2006-06-05 16:31:57 +00:00
|
|
|
trail configuration model, consisting of global flags and naflags parameters,
|
2006-06-05 15:26:09 +00:00
|
|
|
as well as a set of per-auid masks.
|
|
|
|
These parameters are configured using further ioctls.
|
|
|
|
.El
|
|
|
|
.Pp
|
|
|
|
After changing the audit pipe preselection mode, records selected under
|
|
|
|
earlier preselection configuration may still be in the audit pipe queue.
|
|
|
|
The application may flush the current record queue after changing the
|
|
|
|
configuration to remove possibly undesired records.
|
|
|
|
.Ss Audit Pipe Local Preselection Mode Ioctls
|
2006-06-05 16:31:57 +00:00
|
|
|
The following ioctls configure the preselection parameters used when an audit
|
2006-06-05 15:26:09 +00:00
|
|
|
pipe is configured for the
|
|
|
|
.Dv AUDITPIPE_PRESELECT_MODE_LOCAL
|
|
|
|
preselection mode.
|
2006-09-30 15:14:49 +00:00
|
|
|
.Bl -tag -width ".Dv AUDITPIPE_GET_PRESELECT_NAFLAGS"
|
|
|
|
.It Dv AUDITPIPE_GET_PRESELECT_FLAGS
|
2006-06-05 15:26:09 +00:00
|
|
|
Retrieve the current default preselection flags for attributable events on
|
|
|
|
the pipe.
|
|
|
|
These flags correspond to the
|
2006-09-30 15:14:49 +00:00
|
|
|
.Va flags
|
2006-06-05 15:26:09 +00:00
|
|
|
field in
|
|
|
|
.Xr audit_control 5 .
|
|
|
|
The ioctl argument should be of type
|
|
|
|
.Vt u_int .
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_SET_PRESELECT_FLAGS
|
2006-06-05 15:26:09 +00:00
|
|
|
Set the current default preselection flags for attributable events on the
|
|
|
|
pipe.
|
|
|
|
These flags correspond to the
|
2006-09-30 15:14:49 +00:00
|
|
|
.Va flags
|
2006-06-05 15:26:09 +00:00
|
|
|
field in
|
|
|
|
.Xr audit_control 5 .
|
|
|
|
The ioctl argument should be of type
|
|
|
|
.Vt u_int .
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_GET_PRESELECT_NAFLAGS
|
2006-06-05 15:26:09 +00:00
|
|
|
Retrieve the current default preselection flags for non-attributable events
|
|
|
|
on the pipe.
|
|
|
|
These flags correspond to the
|
2006-09-30 15:14:49 +00:00
|
|
|
.Va naflags
|
2006-06-05 15:26:09 +00:00
|
|
|
field in
|
|
|
|
.Xr audit_control 5 .
|
|
|
|
The ioctl argument should be of type
|
|
|
|
.Vt u_int .
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_SET_PRESELECT_NAFLAGS
|
2006-06-05 15:26:09 +00:00
|
|
|
Set the current default preselection flags for non-attributable events on the
|
|
|
|
pipe.
|
|
|
|
These flags correspond to the
|
2006-09-30 15:14:49 +00:00
|
|
|
.Va naflags
|
2006-06-05 15:26:09 +00:00
|
|
|
field in
|
|
|
|
.Xr audit_control 5 .
|
|
|
|
The ioctl argument should be of type
|
|
|
|
.Vt u_int .
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_GET_PRESELECT_AUID
|
2006-06-05 15:26:09 +00:00
|
|
|
Query the current preselection masks for a specific auid on the pipe.
|
|
|
|
The ioctl argument should be of type
|
2006-09-30 15:14:49 +00:00
|
|
|
.Vt "struct auditpipe_preselect" .
|
2006-06-05 15:26:09 +00:00
|
|
|
The auid to query is specified via the
|
|
|
|
.Va ap_auid
|
|
|
|
field of type
|
|
|
|
.Vt au_id_t ;
|
|
|
|
the mask will be returned via
|
|
|
|
.Va ap_mask
|
|
|
|
of type
|
|
|
|
.Vt au_mask_t .
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_SET_PRESELECT_AUID
|
2006-06-05 15:26:09 +00:00
|
|
|
Set the current preselection masks for a specific auid on the pipe.
|
|
|
|
Arguments are identical to
|
2006-09-30 15:14:49 +00:00
|
|
|
.Dv AUDITPIPE_GET_PRESELECT_AUID ,
|
2006-06-05 15:26:09 +00:00
|
|
|
except that the caller should properly initialize the
|
|
|
|
.Va ap_mask
|
|
|
|
field to hold the desired preselection mask.
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_DELETE_PRESELECT_AUID
|
2006-06-05 15:26:09 +00:00
|
|
|
Delete the current preselection mask for a specific auid on the pipe.
|
|
|
|
Once called, events associated with the specified auid will use the default
|
|
|
|
flags mask.
|
|
|
|
The ioctl argument should be of type
|
|
|
|
.Vt au_id_t .
|
2006-09-30 15:14:49 +00:00
|
|
|
.It Dv AUDITPIPE_FLUSH_PRESELECT_AUID
|
2006-06-05 15:26:09 +00:00
|
|
|
Delete all auid specific preselection specifications.
|
|
|
|
.El
|
|
|
|
.Sh EXAMPLES
|
2006-09-30 15:14:49 +00:00
|
|
|
The
|
2006-06-05 15:26:09 +00:00
|
|
|
.Xr praudit 1
|
2006-09-30 15:14:49 +00:00
|
|
|
utility
|
2006-06-05 15:26:09 +00:00
|
|
|
may be directly executed on
|
|
|
|
.Pa /dev/auditpipe
|
|
|
|
to review the default audit trail.
|
|
|
|
.Sh SEE ALSO
|
|
|
|
.Xr poll 2 ,
|
|
|
|
.Xr select 2 ,
|
|
|
|
.Xr audit 4 ,
|
|
|
|
.Xr audit_control 5 ,
|
|
|
|
.Xr audit 8 ,
|
|
|
|
.Xr auditd 8
|
|
|
|
.Sh HISTORY
|
|
|
|
The OpenBSM implementation was created by McAfee Research, the security
|
2006-09-30 15:14:49 +00:00
|
|
|
division of McAfee Inc., under contract to Apple Computer Inc.\& in 2004.
|
2006-06-05 15:26:09 +00:00
|
|
|
It was subsequently adopted by the TrustedBSD Project as the foundation for
|
|
|
|
the OpenBSM distribution.
|
|
|
|
.Pp
|
|
|
|
Support for kernel audit first appeared in
|
|
|
|
.Fx 6.2 .
|
2006-09-30 15:14:49 +00:00
|
|
|
.Sh AUTHORS
|
|
|
|
The audit pipe facility was designed and implemented by
|
|
|
|
.An Robert Watson Aq rwatson@FreeBSD.org .
|
|
|
|
.Pp
|
|
|
|
The Basic Security Module (BSM) interface to audit records and audit event
|
|
|
|
stream format were defined by Sun Microsystems.
|
2006-06-05 15:26:09 +00:00
|
|
|
.Sh BUGS
|
|
|
|
See the
|
|
|
|
.Xr audit 4
|
|
|
|
manual page for information on audit-related bugs and limitations.
|
|
|
|
.Pp
|
|
|
|
The configurable preselection mechanism mirrors the selection model present
|
|
|
|
for the global audit trail.
|
|
|
|
It might be desirable to provided a more flexible selection model.
|
|
|
|
.Pp
|
2006-12-14 16:40:57 +00:00
|
|
|
The per-pipe audit event queue is fifo, with drops occurring if either the
|
2006-06-05 15:26:09 +00:00
|
|
|
user thread provides in sufficient for the record on the queue head, or on
|
|
|
|
enqueue if there is insufficient room.
|
|
|
|
It might be desirable to support partial reads of records, which would be
|
|
|
|
more compatible with buffered I/O as implemented in system libraries, and to
|
|
|
|
allow applications to select which records are dropped, possibly in the style
|
|
|
|
of preselection.
|