Introduce support for per-audit pipe preselection independent from the

global audit trail configuration.  This allows applications consuming
audit trails to specify parameters for which audit records are of
interest, including selecting records not required by the global trail.
Allowing application interest specification without changing the global
configuration allows intrusion detection systems to run without
interfering with global auditing or each other (if multiple are
present).  To implement this:

- Kernel audit records now carry a flag to indicate whether they have
  been selected by the global trail or by the audit pipe subsystem,
  set during record commit, so that this information is available
  after BSM conversion when delivering the BSM to the trail and audit
  pipes in the audit worker thread asynchronously.  Preselection by
  either record target will cause the record to be kept.

- Similar changes to preselection when the audit record is created
  when the system call is entering: consult both the global trail and
  pipes.

- au_preselect() now accepts the class in order to avoid repeatedly
  looking up the mask for each preselection test.

- Define a series of ioctls that allow applications to specify whether
  they want to track the global trail, or program their own
  preselection parameters: they may specify their own flags and naflags
  masks, similar to the global masks of the same name, as well as a set
  of per-auid masks.  They also set a per-pipe mode specifying whether
  they track the global trail, or user their own -- the door is left
  open for future additional modes.  A new ioctl is defined to allow a
  user process to flush the current audit pipe queue, which can be used
  after reprogramming pre-selection to make sure that only records of
  interest are received in future reads.

- Audit pipe data structures are extended to hold the additional fields
  necessary to support preselection.  By default, audit pipes track the
  global trail, so "praudit /dev/auditpipe" will track the global audit
  trail even though praudit doesn't program the audit pipe selection
  model.

- Comment about the complexities of potentially adding partial read
  support to audit pipes.

By using a set of ioctls, applications can select which records are of
interest, and toggle the preselection mode.

Obtained from:	TrustedBSD Project

1 files changed, 32 insertions, 0 deletions

diff --git a/sys/security/audit/audit_ioctl.h b/sys/security/audit/audit_ioctl.h
index af0a389..e80346f 100644
--- a/sys/security/audit/audit_ioctl.h
+++ b/sys/security/audit/audit_ioctl.h
@@ -34,6 +34,25 @@
 #define	AUDITPIPE_IOBASE	'A'
 
 /*
+ * Data structures used for complex ioctl arguments.  Do not change existing
+ * structures, add new revised ones to be used by new ioctls, and keep the
+ * old structures and ioctls for backwards compatibility.
+ */
+struct auditpipe_ioctl_preselect {
+	au_id_t		aip_auid;
+	au_mask_t	aip_mask;
+};
+
+/*
+ * Possible modes of operation for audit pipe preselection.
+ */
+#define	AUDITPIPE_PRESELECT_MODE_TRAIL	1	/* Global audit trail. */
+#define	AUDITPIPE_PRESELECT_MODE_LOCAL	2	/* Local audit trail. */
+#ifdef NOTYET
+#define	AUDITPIPE_PRESELECT_MODE_PRIORITY	3	/* Prioritized trail. */
+#endif
+
+/*
  * Ioctls to read and control the behavior of individual audit pipe devices.
  */
 #define	AUDITPIPE_GET_QLEN		_IOR(AUDITPIPE_IOBASE, 1, u_int)
@@ -41,6 +60,19 @@
 #define	AUDITPIPE_SET_QLIMIT		_IOW(AUDITPIPE_IOBASE, 3, u_int)
 #define	AUDITPIPE_GET_QLIMIT_MIN	_IOR(AUDITPIPE_IOBASE, 4, u_int)
 #define	AUDITPIPE_GET_QLIMIT_MAX	_IOR(AUDITPIPE_IOBASE, 5, u_int)
+#define	AUDITPIPE_GET_PRESELECT_FLAGS	_IOR(AUDITPIPE_IOBASE, 6, au_mask_t)
+#define	AUDITPIPE_SET_PRESELECT_FLAGS	_IOW(AUDITPIPE_IOBASE, 7, au_mask_t)
+#define	AUDITPIPE_GET_PRESELECT_NAFLAGS	_IOR(AUDITPIPE_IOBASE, 8, au_mask_t)
+#define	AUDITPIPE_SET_PRESELECT_NAFLAGS	_IOW(AUDITPIPE_IOBASE, 9, au_mask_t)
+#define	AUDITPIPE_GET_PRESELECT_AUID	_IOR(AUDITPIPE_IOBASE, 10,	\
+					    struct auditpipe_ioctl_preselect)
+#define	AUDITPIPE_SET_PRESELECT_AUID	_IOW(AUDITPIPE_IOBASE, 11,	\
+					    struct auditpipe_ioctl_preselect)
+#define	AUDITPIPE_DELETE_PRESELECT_AUID	_IOW(AUDITPIPE_IOBASE, 12, au_id_t)
+#define	AUDITPIPE_FLUSH_PRESELECT_AUID	_IO(AUDITPIPE_IOBASE, 13)
+#define	AUDITPIPE_GET_PRESELECT_MODE	_IOR(AUDITPIPE_IOBASE, 14, int)
+#define	AUDITPIPE_SET_PRESELECT_MODE	_IOW(AUDITPIPE_IOBASE, 15, int)
+#define	AUDITPIPE_FLUSH			_IO(AUDITPIPE_IOBASE, 16)
 
 /*
  * Ioctls to retrieve audit pipe statistics.