xref: /freebsd/contrib/openbsm/libbsm/au_open.3 (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
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26.\" $P4: //depot/projects/trustedbsd/openbsm/libbsm/au_open.3#8 $
27.\"
28.Dd March 4, 2006
29.Dt AU_OPEN 3
30.Os
31.Sh NAME
32.Nm au_close ,
33.Nm au_close_buffer ,
34.Nm au_close_token ,
35.Nm au_open ,
36.Nm au_write
37.Nd "create and commit audit records"
38.Sh LIBRARY
39.Lb libbsm
40.Sh SYNOPSIS
41.In bsm/libbsm.h
42.Ft int
43.Fn au_open void
44.Ft int
45.Fn au_write "int d" "token_t *tok"
46.Ft int
47.Fn au_close "int d" "int keep" "short event"
48.Ft int
49.Fn au_close_buffer "int d" "short event" "u_char *buffer" "size_t *buflen"
50.Ft int
51.Fn au_close_token "token_t *tok" "u_char *buffer" "size_t *buflen"
52.Sh DESCRIPTION
53These interfaces allow applications to allocate audit records, construct a
54record using a series of tokens, and commit the audit record to the system
55event log.
56An extension API is also provided to commit the record to an in-memory
57buffer rather than the system audit log.
58.Pp
59The
60.Fn au_open
61interface allocates a new audit record descriptor.
62.Pp
63The
64.Fn au_write
65interface adds a token to an allocated audit descriptor.
66When a token has been successfully added to a record, the caller no longer
67owns the token memory, and does not need to free it directly via a call to
68.Xr au_free_token 3 .
69.Pp
70The
71.Fn au_close
72function is used to commit an audit record to the system audit log, or
73abandon the record.
74In either cases, all resources associated with the record will be released.
75The
76.Fa keep
77argument determines the behavior: a value of
78.Dv AU_TO_WRITE
79causes the record to be committed; a value of
80.Dv AU_TO_NO_WRITE
81causes it to be abandoned.
82When the audit record is committed, a BSM header will be inserted before
83tokens added to the record, using the event identifier passed via
84.Fa event ,
85and a trailer added to the end.
86Committing a record to the system audit log requires privilege.
87.Pp
88The
89.Fn au_close_buffer
90function writes the resulting record to an in-memory buffer of size
91.Fa *buflen ;
92it will write back the filled buffer length into the same variable.
93The argument
94.Fa event
95is the event identifier to use in the record header.
96.Pp
97The
98.Fn au_close_token
99function generates the BSM stream output for a single token,
100.Fa tok ,
101in the passed buffer
102.Fa buffer .
103The initial buffer size and resulting data size are passed via
104.Fa *buflen .
105The
106.Fn au_close_token
107function
108will free the token before returning.
109.Sh RETURN VALUES
110The function
111.Fn au_open
112returns a non-negative audit record descriptor number on success, or a
113negative value on failure, along with error information in
114.Va errno .
115.Pp
116The functions
117.Fn au_write ,
118.Fn au_close ,
119.Fn au_close_buffer ,
120and
121.Fn au_close_token
122return 0 on success, or a negative value on failure, along with error
123information in
124.Va errno .
125.Sh SEE ALSO
126.Xr audit_submit 3 ,
127.Xr libbsm 3
128.Sh HISTORY
129The OpenBSM implementation was created by McAfee Research, the security
130division of McAfee Inc., under contract to Apple Computer, Inc., in 2004.
131It was subsequently adopted by the TrustedBSD Project as the foundation for
132the OpenBSM distribution.
133.Sh AUTHORS
134.An -nosplit
135This software was created by
136.An Robert Watson ,
137.An Wayne Salamon ,
138and
139.An Suresh Krishnaswamy
140for McAfee Research, the security research division of McAfee,
141Inc., under contract to Apple Computer, Inc.
142.Pp
143The Basic Security Module (BSM) interface to audit records and audit event
144stream format were defined by Sun Microsystems.
145.Sh BUGS
146Currently,
147.Fn au_open
148does not reserve kernel resources necessary to commit the record to the
149trail; on systems supporting
150.Fn au_close ,
151the call will block until resources are available to commit the record.
152However, this leads to the possibility of an action being permitted without
153the record being guaranteed to go to disk.
154Ideally,
155.Fn au_open
156would reserve resources necessary to commit any submitted record, releasing
157them on
158.Fn au_close .
159