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AU_OPEN(3) FreeBSD Library Functions Manual AU_OPEN(3)
NAME
au_close, au_close_buffer, au_close_token, au_open, au_write - create and
commit audit records
LIBRARY
Basic Security Module Library (libbsm, -lbsm)
SYNOPSIS
#include <bsm/libbsm.h>
int
au_open(void);
int
au_write(int d, token_t *tok);
int
au_close(int d, int keep, short event);
int
au_close_buffer(int d, short event, u_char *buffer, size_t *buflen);
int
au_close_token(token_t *tok, u_char *buffer, size_t *buflen);
DESCRIPTION
These interfaces allow applications to allocate audit records, construct
a record using a series of tokens, and commit the audit record to the
system event log. An extension API is also provided to commit the record
to an in-memory buffer rather than the system audit log.
The au_open() interface allocates a new audit record descriptor.
The au_write() interface adds a token to an allocated audit descriptor.
When a token has been successfully added to a record, the caller no
longer owns the token memory, and does not need to free it directly via a
call to au_free_token(3).
The au_close() function is used to commit an audit record to the system
audit log, or abandon the record. In either cases, all resources
associated with the record will be released. The keep argument
determines the behavior: a value of AU_TO_WRITE causes the record to be
committed; a value of AU_TO_NO_WRITE causes it to be abandoned. When the
audit record is committed, a BSM header will be inserted before tokens
added to the record, using the event identifier passed via event, and a
trailer added to the end. Committing a record to the system audit log
requires privilege.
The au_close_buffer() function writes the resulting record to an in-
memory buffer of size *buflen; it will write back the filled buffer
length into the same variable. The argument event is the event
identifier to use in the record header.
The au_close_token() function generates the BSM stream output for a
single token, tok, in the passed buffer buffer. The initial buffer size
and resulting data size are passed via *buflen. The au_close_token()
function will free the token before returning.
au_close_token() return 0 on success, or a negative value on failure,
along with error information in errno.
SEE ALSO
audit_submit(3), libbsm(3)
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 Robert Watson, Wayne Salamon, and Suresh
Krishnaswamy for McAfee Research, the security research division of
McAfee, Inc., under contract to Apple Computer, Inc.
The Basic Security Module (BSM) interface to audit records and audit
event stream format were defined by Sun Microsystems.
BUGS
Currently, au_open() does not reserve kernel resources necessary to
commit the record to the trail; on systems supporting au_close(), the
call will block until resources are available to commit the record.
However, this leads to the possibility of an action being permitted
without the record being guaranteed to go to disk. Ideally, au_open()
would reserve resources necessary to commit any submitted record,
releasing them on au_close().
FreeBSD 14.0-RELEASE-p11 March 4, 2006 FreeBSD 14.0-RELEASE-p11