freebsd-dev/contrib/openbsm/libbsm/au_open.3
Robert Watson bb97b41819 Vendor import of OpenBSM 1.0 alpha 11, with the following change history
notes since the last import:

OpenBSM 1.0 alpha 11

- Reclassify certain read/write operations as having no class rather than the
  fr/fw class; our default classes audit intent (open) not operations (read,
  write).
- Introduce AUE_SYSCTL_WRITE event so that BSD/Darwin systems can audit reads
  and writes of sysctls as separate events.  Add additional kernel
  environment and jail events for FreeBSD.
- Break AUDIT_TRIGGER_OPEN_NEW into two events, AUDIT_TRIGGER_ROTATE_USER
  (issued by the user audit(8) tool) and AUDIT_TRIGGER_ROTATE_KERNEL (issued
  by the kernel audit implementation) so that they can be distinguished.
- Disable rate limiting of rotate requests; as the kernel doesn't retransmit
  a dropped request, the log file will otherwise grow indefinitely if the
  trigger is dropped.
- Improve auditd debugging output.
- Fix a number of threading related bugs in audit_control file reading
  routines.
- Add APIs au_poltostr() and au_strtopol() to convert between text
  representations of audit_control policy flags and the flags passed to
  auditon(A_SETPOLICY) and retrieved from auditon(A_GETPOLICY).
- Add API getacpol() to return the 'policy:' entry from audit_control, an
  extension to the Solaris file format to allow specification of policy
  persistent flags.
- Update audump to print the audit_control policy field.
- Update auditd to read the audit_control policy field and set the kernel
  policy to match it when configuring/reconfiguring.  Remove the -s and -h
  arguments as these policies are now set via the configuration file.  If a
  policy line is not found in the configuration file, continue with the
  current default of setting AUDIT_CNT.
- Fix bugs in the parsing of large execve(2) arguments and environmental
  variable tokens; increase maximum parsed argument and variable count.
- configure now detects strlcat(), used by policy-related functions.
- Reference token and record sample files added to test tree.

Obtained from:	TrustedBSD Project
2006-09-21 07:07:33 +00:00

152 lines
5.0 KiB
Groff

.\"-
.\" Copyright (c) 2006 Robert N. M. Watson
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.\" $P4: //depot/projects/trustedbsd/openbsm/libbsm/au_open.3#5 $
.\"
.Dd March 4, 2006
.Dt AU_OPEN 3
.Os
.Sh NAME
.Nm au_close ,
.Nm au_close_buffer ,
.Nm au_close_token ,
.Nm au_open ,
.Nm au_write
.Nd "Create and commit audit records"
.Sh LIBRARY
.Lb libbsm
.Sh SYNOPSIS
.In libbsm.h
.Ft int
.Fn au_open "void"
.Ft int
.Fn au_write "int d" "token_t *tok"
.Ft int
.Fn au_close "int d" "int keep" "short event"
.Ft int
.Fn au_close_buffer "int d" "short event" "u_char *buffer" "size_t *buflen"
.Ft int
.Fn au_close_token "token_t *tok" "u_char *buffer" "size_t *buflen"
.Sh 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.
.Pp
The
.Fn au_open
interface allocates a new audit record descriptor.
.Pp
The
.Fn 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
.Xr au_free_token 3 .
.Pp
The
.Fn 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
.Va keep
argument determines the behavior: a value of
.Dv AU_TO_WRITE
causes the record to be committed; a value of
.Dv 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
.Va event ,
and a trailer added to the end.
Committing a record to the system audit log requires privilege.
.Pp
The
.Fn au_close_buffer
function writes the resulting record to an in-memory buffer of size
.Va *buflen ;
it will write back the filled buffer length into the same variable.
The argument
.Va short
is the event identifier to use in the record header.
.Pp
The
.Fn au_close_token
function generates the BSM stream output for a single token,
.Va tok ,
in the passed buffer
.Va buffer .
The initial buffer size and resulting data size are passed via
.Va *buflen .
.Fn au_close_token
will free the token before returning.
.Sh RETURN VALUES
The function
.Fn au_open
returns a non-negative audit record descriptor number on success, or a
negative value on failure, along with error information in
.Va errno .
.Pp
The functions
.Fn au_write ,
.Fn au_close ,
.Fn au_close_buffer ,
and
.Fn au_close_token
return 0 on success, or a negative value on failure, along with error
information in
.Va errno .
.Sh SEE ALSO
.Xr audit_submit 3 ,
.Xr libbsm 3
.Sh 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.
.Pp
The Basic Security Module (BSM) interface to audit records and audit event
stream format were defined by Sun Microsystems.
.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 BUGS
Currently,
.Fn au_open
does not reserve kernel resources necessary to commit the record to the
trail; on systems supporting
.Fn 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,
.Fn au_open
would reserve resources necessary to commit any submitted record, releasing
them on
.Fn au_close .