[PATCH 4/7] MM Auth: introduce AUTH_ERROR constant.

[Neels Hofmeyr]

Instead of using hardcoded -1 for errors, include -1 in the enum auth_action
type; apply its use.

In effect remove a compiler warning recently introduced in auth_action_str()
about int value not represented in enum definition.

In the mm_auth test, the string output changes from '(internal error)' to
'AUTH_ERROR'.
---
 openbsc/include/openbsc/auth.h        | 4 ++--
 openbsc/src/libmsc/auth.c             | 4 ++--
 openbsc/tests/mm_auth/mm_auth_test.c  | 2 +-
 openbsc/tests/mm_auth/mm_auth_test.ok | 2 +-
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/openbsc/include/openbsc/auth.h b/openbsc/include/openbsc/auth.h
index 6c463d4..d8312c3 100644
--- a/openbsc/include/openbsc/auth.h
+++ b/openbsc/include/openbsc/auth.h
@@ -5,6 +5,7 @@ struct gsm_auth_tuple;
 struct gsm_subscriber;
 
 enum auth_action {
+	AUTH_ERROR		= -1,	/* Internal error */
 	AUTH_NOT_AVAIL		= 0,	/* No auth tuple available */
 	AUTH_DO_AUTH_THEN_CIPH	= 1,	/* Firsth authenticate, then cipher */
 	AUTH_DO_CIPH		= 2,	/* Only ciphering */
@@ -17,12 +18,11 @@ static inline const char *auth_action_str(enum auth_action a)
 	case X: return #X
 
 	switch (a) {
+	AUTH_CASE(AUTH_ERROR);
 	AUTH_CASE(AUTH_NOT_AVAIL);
 	AUTH_CASE(AUTH_DO_AUTH_THEN_CIPH);
 	AUTH_CASE(AUTH_DO_CIPH);
 	AUTH_CASE(AUTH_DO_AUTH);
-	case -1:
-		return "(internal error)";
 	default:
 		return "(unknown auth_action)";
 	}
diff --git a/openbsc/src/libmsc/auth.c b/openbsc/src/libmsc/auth.c
index 65a9b03..68ba8c3 100644
--- a/openbsc/src/libmsc/auth.c
+++ b/openbsc/src/libmsc/auth.c
@@ -84,7 +84,7 @@ int auth_get_tuple_for_subscr(struct gsm_auth_tuple *atuple,
 	if (rc < 0) {
 		LOGP(DMM, LOGL_NOTICE,
 			"No retrievable Ki for subscriber, skipping auth\n");
-		return rc == -ENOENT ? AUTH_NOT_AVAIL : -1;
+		return rc == -ENOENT ? AUTH_NOT_AVAIL : AUTH_ERROR;
 	}
 
 	/* If possible, re-use the last tuple and skip auth */
@@ -105,7 +105,7 @@ int auth_get_tuple_for_subscr(struct gsm_auth_tuple *atuple,
 
 	if (RAND_bytes(atuple->rand, sizeof(atuple->rand)) != 1) {
 		LOGP(DMM, LOGL_NOTICE, "RAND_bytes failed, can't generate new auth tuple\n");
-		return -1;
+		return AUTH_ERROR;
 	}
 
 	switch (ainfo.auth_algo) {
diff --git a/openbsc/tests/mm_auth/mm_auth_test.c b/openbsc/tests/mm_auth/mm_auth_test.c
index e541898..1d65984 100644
--- a/openbsc/tests/mm_auth/mm_auth_test.c
+++ b/openbsc/tests/mm_auth/mm_auth_test.c
@@ -141,7 +141,7 @@ static void test_error()
 	test_get_authinfo_rc = -EIO;
 	auth_action = auth_get_tuple_for_subscr_verbose(&atuple, &subscr,
 							key_seq);
-	OSMO_ASSERT(auth_action == -1);
+	OSMO_ASSERT(auth_action == AUTH_ERROR);
 }
 
 static void test_auth_not_avail()
diff --git a/openbsc/tests/mm_auth/mm_auth_test.ok b/openbsc/tests/mm_auth/mm_auth_test.ok
index cc0e769..7dedadc 100644
--- a/openbsc/tests/mm_auth/mm_auth_test.ok
+++ b/openbsc/tests/mm_auth/mm_auth_test.ok
@@ -1,7 +1,7 @@
 
 * test_error()
 wrapped: db_get_authinfo_for_subscr(): rc = -5
-auth_get_tuple_for_subscr(key_seq=0) --> auth_action == (internal error)
+auth_get_tuple_for_subscr(key_seq=0) --> auth_action == AUTH_ERROR
 
 * test_auth_not_avail()
 wrapped: db_get_authinfo_for_subscr(): rc = -2
-- 
2.1.4