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.Dd March 23, 2009
.Dt SETAUDIT 2
.Os
.Sh NAME
.Nm setaudit ,
.Nm setaudit_addr
.Nd "set audit session state"
.Sh SYNOPSIS
.In bsm/audit.h
.Ft int
.Fn setaudit "auditinfo_t *auditinfo"
.Ft int
.Fn setaudit_addr "auditinfo_addr_t *auditinfo_addr" "u_int length"
.Sh DESCRIPTION
The
.Fn setaudit
system call
sets the active audit session state for the current process via the
.Vt auditinfo_t
pointed to by
.Fa auditinfo .
The
.Fn setaudit_addr
system call
sets extended state via
.Fa auditinfo_addr
and
.Fa length .
.Pp
The
.Fa auditinfo_t
data structure is defined as follows:
.nf
.in +4n
struct auditinfo {
	au_id_t        ai_auid;         /* Audit user ID */
	au_mask_t      ai_mask;         /* Audit masks */
	au_tid_t       ai_termid;       /* Terminal ID */
	au_asid_t      ai_asid;         /* Audit session ID */
};
typedef struct auditinfo        auditinfo_t;
.in
.fi
.Pp
The
.Fa ai_auid
variable contains the audit identifier which is recorded in the audit log for 
each event the process caused.
The value of AU_DEFAUDITID (-1) should not be used.
The exception is if the value of audit identifier is known at the
start of the session but will be determined and set later.
Until 
.Fa ai_auid
is set to something other than AU_DEFAUDITID any audit events
generated by the system with be filtered by the non-attributed audit
mask.
.Pp
The
.Fa au_mask_t
data structure defines the bit mask for auditing successful and failed events 
out of the predefined list of event classes. It is defined as follows:
.nf
.in +4n
struct au_mask {
	unsigned int    am_success;     /* success bits */
	unsigned int    am_failure;     /* failure bits */
};
typedef struct au_mask  au_mask_t;
.in
.fi
.Pp
The
.Fa au_termid_t
data structure defines the Terminal ID recorded with every event caused by the 
process. It is defined as follows:
.nf
.in +4n
struct au_tid {
	dev_t           port;
	u_int32_t       machine;
};
typedef struct au_tid   au_tid_t;
.in
.fi
.Pp
The
.Fa ai_asid
variable contains the audit session ID which is recorded with every event 
caused by the process.  It can be any value in the range 1 to PID_MAX (99999).
If the value of AU_ASSIGN_ASID is used for 
.Fa ai_asid
a unique session ID will be generated by the kernel.
The audit session ID will be returned in the
.Fa ai_asid
field on success.
.Pp
The
.Fn setaudit_addr
system call
uses the expanded
.Fa auditinfo_addr_t 
data structure which supports Terminal IDs with larger addresses
such as those used in IP version 6.  It is defined as follows:
.nf
.in +4n
struct auditinfo_addr {
	au_id_t         ai_auid;        /* Audit user ID. */
	au_mask_t       ai_mask;        /* Audit masks. */
	au_tid_addr_t   ai_termid;      /* Terminal ID. */
	au_asid_t       ai_asid;        /* Audit session ID. */
	u_int64_t       ai_flags;       /* Audit session flags */
};
typedef struct auditinfo_addr   auditinfo_addr_t;
.in
.fi
.Pp
The 
.Fa au_tid_addr_t
data structure includes a larger address storage field and an additional
field with the type of address stored:
.nf
.in +4n
struct au_tid_addr {
	dev_t           at_port;
	u_int32_t       at_type;
	u_int32_t       at_addr[4];
};
typedef struct au_tid_addr      au_tid_addr_t;
.in
.fi
.Pp
The
.Fa ai_flags
field is opaque to the kernel and can be used to store user
defined session flags.
.Pp
These system calls require an appropriate privilege to complete.
.Pp
These system calls should only be called once at the start of a new
session and not again during the same session to update the session 
information.
There are some exceptions, however.
The 
.Fa ai_auid
field may be updated later if initially set to the value of
AU_DEFAUDITID (-1).
Likewise, the 
.Fa ai_termid
fields may be updated later if the 
.Fa at_type
field in
.Fa au_tid_addr
is set to AU_IPv4 and the other
.Fa ai_tid_addr
fields are all set to zero.
Creating a new session is done by setting the 
.Fa ai_asid
field to an unique session value or AU_ASSIGN_ASID.
These system calls will fail when attempting to change the
.Fa ai_auid
or
.Fa ai_termid
fields once set to something other than the default values.
The
.Fa ai_flags
field may be updated only according to local access control
policy but this is usually accomplished with
.Xr auditon 2
using the A_SETSFLAGS command.
The audit preselection masks may be changed at any time
but are usually updated with
.Xr auditon 2
using the A_SETPMASK command.
.Sh RETURN VALUES
.Rv -std setaudit setaudit_addr
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er EFAULT
A failure occurred while data transferred to or from
the kernel failed.
.It Bq Er EINVAL
Illegal argument was passed by a system call.
.It Bq Er EPERM
The process does not have sufficient permission to complete
the operation.
.El
.Sh SEE ALSO
.Xr audit 2 ,
.Xr auditon 2 ,
.Xr getaudit 2 ,
.Xr getauid 2 ,
.Xr setauid 2 ,
.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.
.Sh AUTHORS
.An -nosplit
This software was created by McAfee Research, the security research division
of McAfee, Inc., under contract to Apple Computer Inc.
Additional authors include
.An Wayne Salamon ,
.An Robert Watson ,
and SPARTA Inc.
.Pp
The Basic Security Module (BSM) interface to audit records and audit event
stream format were defined by Sun Microsystems.
.Pp
This manual page was written by
.An Robert Watson Aq rwatson@FreeBSD.org
and
.An Stacey Son Aq sson@FreeBSD.org .