ima: generic IMA action flag handling

Make the IMA action flag handling generic in order to support
additional new actions, without requiring changes to the base
implementation.  New actions, like audit logging, will only
need to modify the define statements.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

4 files changed, 26 insertions, 19 deletions

diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 4cdf36ad884a..0aa43bde441c 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -232,7 +232,7 @@ static void ima_reset_appraise_flags(struct inode *inode)
         if (!iint)
                 return;
 
-        iint->flags &= ~(IMA_COLLECTED | IMA_APPRAISED | IMA_MEASURED);
+        iint->flags &= ~IMA_DONE_MASK;
         return;
 }
 
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 60b047e96f4e..5da08b75d367 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -117,7 +117,7 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint,
         mutex_lock(&inode->i_mutex);
         if (atomic_read(&inode->i_writecount) == 1 &&
             iint->version != inode->i_version) {
-                iint->flags &= ~(IMA_COLLECTED | IMA_APPRAISED | IMA_MEASURED);
+                iint->flags &= ~IMA_DONE_MASK;
                 if (iint->flags & IMA_APPRAISE)
                         ima_update_xattr(iint, file);
         }
@@ -173,7 +173,7 @@ static int process_measurement(struct file *file, const unsigned char *filename,
         /* Determine if already appraised/measured based on bitmask
          * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED) */
         iint->flags |= action;
-        action &= ~((iint->flags & (IMA_MEASURED | IMA_APPRAISED)) >> 1);
+        action &= ~((iint->flags & IMA_DONE_MASK) >> 1);
 
         /* Nothing to do, just return existing appraised status */
         if (!action) {
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 0d6d60b4ba6f..f46f685a1711 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -26,13 +26,11 @@
 #define IMA_UID         0x0008
 #define IMA_FOWNER      0x0010
 
-#define UNKNOWN                 0
-#define MEASURE                 1       /* same as IMA_MEASURE */
-#define DONT_MEASURE            2
-#define MEASURE_MASK            3
-#define APPRAISE                4       /* same as IMA_APPRAISE */
-#define DONT_APPRAISE           8
-#define APPRAISE_MASK           12
+#define UNKNOWN         0
+#define MEASURE         0x0001  /* same as IMA_MEASURE */
+#define DONT_MEASURE    0x0002
+#define APPRAISE        0x0004  /* same as IMA_APPRAISE */
+#define DONT_APPRAISE   0x0008
 
 #define MAX_LSM_RULES 6
 enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
@@ -209,9 +207,12 @@ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
                 if (!ima_match_rules(entry, inode, func, mask))
                         continue;
 
-                action |= (entry->action & (IMA_APPRAISE | IMA_MEASURE));
-                actmask &= (entry->action & APPRAISE_MASK) ?
-                    ~APPRAISE_MASK : ~MEASURE_MASK;
+                action |= entry->action & IMA_DO_MASK;
+                if (entry->action & IMA_DO_MASK)
+                        actmask &= ~(entry->action | entry->action << 1);
+                else
+                        actmask &= ~(entry->action | entry->action >> 1);
+
                 if (!actmask)
                         break;
         }
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 4eec1b14193e..564ba7db5f6a 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -15,13 +15,19 @@
 #include <linux/integrity.h>
 #include <crypto/sha.h>
 
+/* iint action cache flags */
+#define IMA_MEASURE             0x0001
+#define IMA_MEASURED            0x0002
+#define IMA_APPRAISE            0x0004
+#define IMA_APPRAISED           0x0008
+/*#define IMA_COLLECT           0x0010  do not use this flag */
+#define IMA_COLLECTED           0x0020
+
 /* iint cache flags */
-#define IMA_MEASURE             0x01
-#define IMA_MEASURED            0x02
-#define IMA_APPRAISE            0x04
-#define IMA_APPRAISED           0x08
-#define IMA_COLLECTED           0x10
-#define IMA_DIGSIG              0x20
+#define IMA_DIGSIG              0x0100
+
+#define IMA_DO_MASK             (IMA_MEASURE | IMA_APPRAISE)
+#define IMA_DONE_MASK           (IMA_MEASURED | IMA_APPRAISED | IMA_COLLECTED)
 
 enum evm_ima_xattr_type {
         IMA_XATTR_DIGEST = 0x01,