[PATCH] add rule filterkey
Add support for a rule key, which can be used to tie audit records to audit
rules. This is useful when a watched file is accessed through a link or
symlink, as well as for general audit log analysis.
Because this patch uses a string key instead of an integer key, there is a bit
of extra overhead to do the kstrdup() when a rule fires. However, we're also
allocating memory for the audit record buffer, so it's probably not that
significant. I went ahead with a string key because it seems more
user-friendly.
Note that the user must ensure that filterkeys are unique. The kernel only
checks for duplicate rules.
Signed-off-by: Amy Griffis <amy.griffis@hpd.com>
diff --git a/include/linux/audit.h b/include/linux/audit.h
index e051ff9..a489104 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -122,6 +122,7 @@
/* Rule structure sizes -- if these change, different AUDIT_ADD and
* AUDIT_LIST commands must be implemented. */
#define AUDIT_MAX_FIELDS 64
+#define AUDIT_MAX_KEY_LEN 32
#define AUDIT_BITMASK_SIZE 64
#define AUDIT_WORD(nr) ((__u32)((nr)/32))
#define AUDIT_BIT(nr) (1 << ((nr) - AUDIT_WORD(nr)*32))
@@ -171,6 +172,8 @@
#define AUDIT_ARG2 (AUDIT_ARG0+2)
#define AUDIT_ARG3 (AUDIT_ARG0+3)
+#define AUDIT_FILTERKEY 210
+
#define AUDIT_NEGATE 0x80000000
/* These are the supported operators.