AUDITON(2) BSD System Calls Manual AUDITON(2)
auditon -- configure system audit parameters
auditon(int cmd, void *data, u_int length);
The auditon() system call is used to manipulate various audit control operations. The data argument should point to a structure whose type
depends on the command. The length argument specifies the size of *data in bytes. The cmd argument may be any of the following:
A_SETPOLICY Set audit policy flags. The data argument must point to a int value set to one or more the following audit policy control
values bitwise OR'ed together: AUDIT_CNT, AUDIT_AHLT, AUDIT_ARGV, and AUDIT_ARGE. If AUDIT_CNT is set, the system will
continue even if it becomes low on space and discontinue logging events until the low space condition is remedied. If it is
not set, audited events will block until the low space condition is remedied. Unaudited events, however, are unaffected.
If AUDIT_AHLT is set, a panic(9) if it cannot write an event to the global audit log file. If AUDIT_ARGV is set, then the
argument list passed to the execve(2) system call will be audited. If AUDIT_ARGE is set, then the environment variables
passed to the execve(2) system call will be audited. The default policy is none of the audit policy control flags set.
A_SETKAUDIT Set the host information. The data argument must point to a auditinfo_addr_t structure containing the host IP address
information. After setting, audit records that are created as a result of kernel events will contain this information.
A_SETKMASK Set the kernel preselection masks (success and failure). The data argument must point to a au_mask_t structure containing
the mask values as defined in <bsm/audit.h>. These masks are used for non-attributable audit event preselection. The field
am_success specifies which classes of successful audit events are to be logged to the audit trail. The field am_failure
specifies which classes of failed audit events are to be logged. The value of both fields is the bitwise OR'ing of the audit
event classes specified in bsm/audit.h. The various audit classes are described more fully in audit_class(5).
A_SETQCTRL Set kernel audit queue parameters. The data argument must point to a au_qctrl_t structure (defined in <bsm/audit.h>) con-
taining the kernel audit queue control settings: aq_hiwater, aq_lowater, aq_bufsz, aq_delay, and aq_minfree. The field
aq_hiwater defines the maximum number of audit record entries in the queue used to store the audit records ready for deliv-
ery to disk. New records are inserted at the tail of the queue and removed from the head. For new records which would
exceed the high water mark, the calling thread is inserted into the wait queue, waiting for the audit queue to have enough
space available as defined with the field aq_lowater. The field aq_bufsz defines the maximum length of the audit record
that can be supplied with audit(2). The field aq_delay is unused. The field aq_minfree specifies the minimum amount of
free blocks on the disk device used to store audit records. If the value of free blocks falls below the configured minimum
amount, the kernel informs the audit daemon about low disk space. The value is to be specified in percent of free file sys-
tem blocks. A value of 0 results in a disabling of the check. The default and maximum values (default/maximum) for the
audit queue control parameters are:
aq_hiwater 100/10000 (audit records)
aq_lowater 10/aq_hiwater (audit records)
aq_bufsz 32767/1048576 (bytes)
aq_delay (Not currently used.)
A_SETSTAT Return ENOSYS. (Not implemented.)
A_SETUMASK Return ENOSYS. (Not implemented.)
A_SETSMASK Return ENOSYS. (Not implemented.)
A_SETCOND Set the current auditing condition. The data argument must point to a int value containing the new audit condition, one of
AUC_AUDITING, AUC_NOAUDIT, or AUC_DISABLED. If AUC_NOAUDIT is set, then auditing is temporarily suspended. If AUC_AUDITING
is set, auditing is resumed. If AUC_DISABLED is set, the auditing system will shutdown, draining all audit records and clos-
ing out the audit trail file.
A_SETCLASS Set the event class preselection mask for an audit event. The data argument must point to a au_evclass_map_t structure con-
taining the audit event and mask. The field ec_number is the audit event and ec_class is the audit class mask. See
audit_event(5) for more information on audit event to class mapping.
A_SETPMASK Set the preselection masks for a process. The data argument must point to a auditpinfo_t structure that contains the given
process's audit preselection masks for both success and failure. The field ap_pid is the process id of the target process.
The field ap_mask must point to a au_mask_t structure which holds the preselection masks as described in the section above.
A_SETFSIZE Set the maximum size of the audit log file. The data argument must point to a au_fstat_t structure with the af_filesz field
set to the maximum audit log file size. A value of 0 indicates no limit to the size.
A_SETSFLAGS Set the audit sessions flags for the current session. The data argument must point to an au_asflgs_t value containing the
new audit session flags. Audit session flags may be updated only according to local access control policy.
A_GETCLASS Return the event to class mapping for the designated audit event. The data argument must point to a au_evclass_map_t struc-
ture. See the A_SETCLASS section above for more information.
A_GETKAUDIT Get the current host information. The data argument must point to a auditinfo_addr_t structure.
A_GETPINFO Return the audit settings for a process. The data argument must point to a auditpinfo_t structure which will be set to con-
tain ap_auid (the audit ID), ap_mask (the preselection mask), ap_termid (the terminal ID), and ap_asid (the audit session
ID) of the given target process. The process ID of the target process is passed into the kernel using the ap_pid field.
See the section A_SETPMASK above and getaudit(2) for more information.
A_GETPINFO_ADDR Return the extended audit settings for a process. The data argument must point to a auditpinfo_addr_t structure which is
similar to the auditpinfo_addr_t structure described above. The exception is the ap_termid (the terminal ID) field which
points to a au_tid_addr_t structure can hold much a larger terminal address and an address type. The process ID of the tar-
get process is passed into the kernel using the ap_pid field. See the section A_SETPMASK above and getaudit(2) for more
A_GETSINFO_ADDR Return the extended audit settings for a session. The data argument must point to a auditinfo_addr_t structure. The audit
session ID of the target session is passed into the kernel using the ai_asid field. See getaudit_addr(2) for more informa-
tion about the auditinfo_addr_t structure.
A_GETKMASK Return the current kernel preselection masks. The data argument must point to a au_mask_t structure which will be set to
the current kernel preselection masks for non-attributable events.
A_GETPOLICY Return the current audit policy setting. The data argument must point to a int value which will be set to one of the cur-
rent audit policy flags. The audit policy flags are described in the A_SETPOLICY section above.
A_GETQCTRL Return the current kernel audit queue control parameters. The data argument must point to a au_qctrl_t structure which will
be set to the current kernel audit queue control parameters. See the A_SETQCTL section above for more information.
A_GETFSIZE Returns the maximum size of the audit log file. The data argument must point to a au_fstat_t structure. The af_filesz
field will be set to the maximum audit log file size. A value of 0 indicates no limit to the size. The af_currsz field
will be set to the current audit log file size.
A_GETSFLAGS Returns the audit session flags for the current session. The data argument must point to an au_asflgs_t value which will be
set with the current session flags.
A_GETCWD Return ENOSYS. (Not implemented.)
A_GETCAR Return ENOSYS. (Not implemented.)
A_GETSTAT Return ENOSYS. (Not implemented.)
A_GETCOND Return the current auditing condition. The data argument must point to a int value which will be set to the current audit
condition, one of AUC_AUDITING, AUC_NOAUDIT or AUC_DISABLED. See the A_SETCOND section above for more information.
A_SENDTRIGGER Send a trigger to the audit daemon. The data argument must point to a int value set to one of the acceptable trigger val-
ues: AUDIT_TRIGGER_LOW_SPACE (low disk space where the audit log resides), AUDIT_TRIGGER_OPEN_NEW (open a new audit log
file), AUDIT_TRIGGER_READ_FILE (read the audit_control file), AUDIT_TRIGGER_CLOSE_AND_DIE (close the current log file and
exit), AUDIT_TRIGGER_NO_SPACE (no disk space left for audit log file). AUDIT_TRIGGER_ROTATE_USER (request audit log file
rotation). AUDIT_TRIGGER_INITIALIZE (initialize audit subsystem for Mac OS X only). or AUDIT_TRIGGER_EXPIRE_TRAILS
(request audit log file expiration).
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the
The auditon() function will fail if:
[ENOSYS] Returned by options not yet implemented.
[EFAULT] A failure occurred while data transferred to or from the kernel failed.
[EINVAL] Illegal argument was passed by a system call.
[EPERM] The process does not have sufficient permission to complete the operation.
The A_SENDTRIGGER command is specific to the FreeBSD and Mac OS X implementations, and is not present in Solaris.
audit(2), auditctl(2), getaudit(2), getaudit_addr(2), getauid(2), setaudit(2), setaudit_addr(2), setauid(2), libbsm(3)
The OpenBSM implementation was created by McAfee Research, the security division of McAfee Inc., under contract to Apple Computer Inc. in
2004. It was subsequently adopted by the TrustedBSD Project as the foundation for the OpenBSM distribution.
This software was created by McAfee Research, the security research division of McAfee, Inc., under contract to Apple Computer Inc. Addi-
tional authors include Wayne Salamon, Robert Watson, and SPARTA Inc.
The Basic Security Module (BSM) interface to audit records and audit event stream format were defined by Sun Microsystems.
This manual page was written by Tom Rhodes <trhodes@FreeBSD.org>, Robert Watson <rwatson@FreeBSD.org>, and Wayne Salamon
January 29, 2009 BSD