NAME

auditon —

configure system audit parameters

SYNOPSIS

#include <bsm/audit.h>

int
auditon(int cmd, void *data, u_int length);

DESCRIPTION

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>) containing 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 delivery 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 system 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 closing 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 containing 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 A_SETKMASK 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_GETCLASS

Return the event to class mapping for the designated audit event. The data argument must point to a au_evclass_map_t structure. 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 contain 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_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 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_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 information 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 current 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_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 values: 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).

RETURN VALUES

Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

ERRORS

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.

HISTORY

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.

AUTHORS

This software was created by McAfee Research, the security research division of McAfee, Inc., under contract to Apple Computer Inc. Additional 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 ⟨wsalamon@FreeBSD.org⟩.