.\"-
.\" Copyright (c) 2009 Apple, Inc.
.\" Copyright (c) 2005 Robert N. M. Watson
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.Dd May 30, 2018
.Dt AU_IO 3
.Os
.Sh NAME
.Nm au_fetch_tok ,
.Nm au_print_tok ,
.Nm au_print_flags_tok ,
.Nm au_read_rec
.Nd "perform I/O involving an audit record"
.Sh LIBRARY
.Lb libbsm
.Sh SYNOPSIS
.In bsm/libbsm.h
.Ft int
.Fn au_fetch_tok "tokenstr_t *tok" "u_char *buf" "int len"
.Ft void
.Fo au_print_tok
.Fa "FILE *outfp" "tokenstr_t *tok" "char *del" "char raw" "char sfrm"
.Fc
.Ft void
.Fo au_print_flags_tok
.Fa "FILE *outfp" "tokenstr_t *tok" "char *del" "int oflags"
.Fc
.Ft int
.Fn au_read_rec "FILE *fp" "u_char **buf"
.Sh DESCRIPTION
These interfaces support input and output (I/O) involving audit records,
internalizing an audit record from a byte stream, converting a token to
either a raw or default string, and reading a single record from a file.
.Pp
The
.Fn au_fetch_tok
function
reads a token from the passed buffer
.Fa buf
of length
.Fa len
bytes, and returns a pointer to the token via
.Fa tok .
.Pp
The
.Fn au_print_tok
function
prints a string form of the token
.Fa tok
to the file output stream
.Fa outfp ,
either in default mode, or raw mode if
.Fa raw
is set non-zero.
The delimiter
.Fa del
is used when printing.
The
.Fn au_print_flags_tok
function is a replacement for
.Fn au_print_tok .
The
.Fa oflags
controls how the output should be formatted and is specified by
or'ing the following flags:
.Pp
.Bl -tag -width AU_OFLAG_NORESOLVE -compact -offset indent
.It Li AU_OFLAG_NONE
Use the default form.
.It Li AU_OFLAG_NORESOLVE
Leave user and group IDs in their numeric form.
.It Li AU_OFLAG_RAW
Use the raw, numeric form.
.It Li AU_OFLAG_SHORT
Use the short form.
.It Li AU_OFLAG_XML
Use the XML form.
.El
.Pp
The flags options AU_OFLAG_SHORT and AU_OFLAG_RAW are exclusive and
should not be used together.
.Pp
The
.Fn au_read_rec
function
reads an audit record from the file stream
.Fa fp ,
and returns an allocated memory buffer containing the record via
.Fa *buf ,
which must be freed by the caller using
.Xr free 3 .
.Pp
A typical use of these routines might open a file with
.Xr fopen 3 ,
then read records from the file sequentially by calling
.Fn au_read_rec .
Each record would be broken down into components tokens through sequential
calls to
.Fn au_fetch_tok
on the buffer, and then invoking
.Fn au_print_flags_tok
to print each token to an output stream such as
.Dv stdout .
On completion of the processing of each record, a call to
.Xr free 3
would be used to free the record buffer.
Finally, the source stream would be closed by a call to
.Xr fclose 3 .
.Sh RETURN VALUES
On success,
.Fn au_fetch_tok
returns 0 while
.Fn au_read_rec
returns the number of bytes read.
Both functions return \-1 on failure with
.Va errno
set appropriately.
.Sh SEE ALSO
.Xr free 3 ,
.Xr libbsm 3
.Sh 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.
.Pp
The
.Fn au_print_flags_tok
function was added by Stacey Son as a replacement for the
.Fn au_print_tok
so new output formatting flags can be easily added without changing the API.
The
.Fn au_print_tok
is obsolete but remains in the API to support legacy code.
.Sh AUTHORS
.An -nosplit
This software was created by
.An Robert Watson ,
.An Wayne Salamon ,
and
.An Suresh Krishnaswamy
for McAfee Research, the security research division of McAfee,
Inc., under contract to Apple Computer, Inc.
.Pp
The Basic Security Module (BSM) interface to audit records and audit event
stream format were defined by Sun Microsystems.
.Sh BUGS
The
.Va errno
variable
may not always be properly set in the event of an error.