[PATCH] filterexcl: allow filterkey

[Richard Guy Briggs]

The exclude rules did not permit a filterkey to be added.  This isn't as
important for the exclude filter compared to the others since no records are
generated with that key, but still helps identify rules in the rules list
configuration.

Allow filterkeys to be used with the exclude filter.

See: https://github.com/linux-audit/audit-userspace/issues/14

Signed-off-by: Richard Guy Briggs <rgb at redhat.com>
---
 lib/libaudit.c |   13 +++++++++++--
 lib/private.h  |    1 +
 src/auditctl.c |    5 +++--
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/lib/libaudit.c b/lib/libaudit.c
index b1f8f9c..028483d 100644
--- a/lib/libaudit.c
+++ b/lib/libaudit.c
@@ -85,6 +85,7 @@ int _audit_permadded = 0;
 int _audit_archadded = 0;
 int _audit_syscalladded = 0;
 int _audit_exeadded = 0;
+int _audit_filterexcladded = 0;
 unsigned int _audit_elf = 0U;
 static struct libaudit_conf config;
 
@@ -1445,8 +1446,14 @@ int audit_rule_fieldpair_data(struct audit_rule_data **rulep, const char *pair,
 	if (flags == AUDIT_FILTER_EXCLUDE) {
 		uint32_t features = audit_get_features();
 		if ((features & AUDIT_FEATURE_BITMAP_EXCLUDE_EXTEND) == 0) {
-			if (field != AUDIT_MSGTYPE)
+			switch(field) {
+			case AUDIT_MSGTYPE:
+				_audit_filterexcladded = 1;
+			case AUDIT_FILTERKEY:
+				break;
+			default:
 				return -EAU_FIELDNOSUPPORT;
+			}
 		} else {
 			switch(field) {
 				case AUDIT_PID:
@@ -1459,6 +1466,8 @@ int audit_rule_fieldpair_data(struct audit_rule_data **rulep, const char *pair,
 				case AUDIT_SUBJ_TYPE:
 				case AUDIT_SUBJ_SEN:
 				case AUDIT_SUBJ_CLR:
+					_audit_filterexcladded = 1;
+				case AUDIT_FILTERKEY:
 					break;
 				default:
 					return -EAU_MSGTYPECREDEXCLUDE;
@@ -1580,7 +1589,7 @@ int audit_rule_fieldpair_data(struct audit_rule_data **rulep, const char *pair,
 			}
 			if (field == AUDIT_FILTERKEY &&
 				!(_audit_syscalladded || _audit_permadded ||
-				_audit_exeadded))
+				_audit_exeadded || _audit_filterexcladded))
                                 return -EAU_KEYDEP;
 			vlen = strlen(v);
 			if (field == AUDIT_FILTERKEY &&
diff --git a/lib/private.h b/lib/private.h
index cde1906..855187b 100644
--- a/lib/private.h
+++ b/lib/private.h
@@ -139,6 +139,7 @@ extern int _audit_permadded;
 extern int _audit_archadded;
 extern int _audit_syscalladded;
 extern int _audit_exeadded;
+extern int _audit_filterexcladded;
 extern unsigned int _audit_elf;
 
 #ifdef __cplusplus
diff --git a/src/auditctl.c b/src/auditctl.c
index 04765f4..c785087 100644
--- a/src/auditctl.c
+++ b/src/auditctl.c
@@ -74,6 +74,7 @@ static int reset_vars(void)
 	_audit_permadded = 0;
 	_audit_archadded = 0;
 	_audit_exeadded = 0;
+	_audit_filterexcladded = 0;
 	_audit_elf = 0;
 	add = AUDIT_FILTER_UNSET;
 	del = AUDIT_FILTER_UNSET;
@@ -936,8 +937,8 @@ static int setopt(int count, int lineno, char *vars[])
 		break;
 	case 'k':
 		if (!(_audit_syscalladded || _audit_permadded ||
-			     _audit_exeadded) || (add==AUDIT_FILTER_UNSET &&
-					del==AUDIT_FILTER_UNSET)) {
+		      _audit_exeadded || _audit_filterexcladded) ||
+		    (add==AUDIT_FILTER_UNSET && del==AUDIT_FILTER_UNSET)) {
 			audit_msg(LOG_ERR,
 		    "key option needs a watch or syscall given prior to it");
 			retval = -1;
-- 
1.7.1