refactor VLR FSM result handling

Instead of keeping separate enums for FSM results and translating between those
and the actual 04.08 reject causes that will ultimately reach the MS, just pass
enum gsm48_reject_value cause codes around everywhere.

Collapse some VLR *_timeout() and *_cancel() api to just *_cancel() with a
gsm48 cause arg.

(Hopefully) improve a few reject causes, but otherwise just aim for more
transparent decisions on which cause value is used, for future fixes of
returned causes.

Depends: I6661f139e68a498fb1bef10c266c2f064b72774a (libosmocore)
Change-Id: I27bf8d68737ff1f8dc6d11fb1eac3d391aab0cb1

1 files changed, 22 insertions, 42 deletions

diff --git a/src/libvlr/vlr_lu_fsm.c b/src/libvlr/vlr_lu_fsm.c
index 908e0e3ca..3073bd6dc 100644
--- a/src/libvlr/vlr_lu_fsm.c
+++ b/src/libvlr/vlr_lu_fsm.c
@@ -741,11 +741,10 @@ static void lu_fsm_success(struct osmo_fsm_inst *fi)
 	_lu_fsm_done(fi, VLR_FSM_RESULT_SUCCESS);
 }
 
-static void lu_fsm_failure(struct osmo_fsm_inst *fi, uint8_t rej_cause)
+static void lu_fsm_failure(struct osmo_fsm_inst *fi, enum gsm48_reject_value rej_cause)
 {
 	struct lu_fsm_priv *lfp = lu_fsm_fi_priv(fi);
-	if (rej_cause)
-		lfp->vlr->ops.tx_lu_rej(lfp->msc_conn_ref, rej_cause);
+	lfp->vlr->ops.tx_lu_rej(lfp->msc_conn_ref, rej_cause ? : GSM48_REJECT_NETWORK_FAILURE);
 	_lu_fsm_done(fi, VLR_FSM_RESULT_FAILURE);
 }
 
@@ -1097,44 +1096,19 @@ static void lu_fsm_wait_auth(struct osmo_fsm_inst *fi, uint32_t event,
 			     void *data)
 {
 	struct lu_fsm_priv *lfp = lu_fsm_fi_priv(fi);
-	enum vlr_auth_fsm_result *res = data;
-	uint8_t rej_cause = 0;
+	enum gsm48_reject_value *res = data;
 
 	OSMO_ASSERT(event == VLR_ULA_E_AUTH_RES);
 
 	lfp->upd_hlr_vlr_fsm = NULL;
 
-	if (res) {
-		switch (*res) {
-		case VLR_AUTH_RES_PASSED:
-			/* Result == Pass */
-			vlr_loc_upd_post_auth(fi);
-			return;
-		case VLR_AUTH_RES_ABORTED:
-			/* go to Idle with no response */
-			rej_cause = 0;
-			break;
-		case VLR_AUTH_RES_UNKNOWN_SUBSCR:
-			/* FIXME: delete subscribe record */
-			rej_cause = GSM48_REJECT_IMSI_UNKNOWN_IN_HLR;
-			break;
-		case VLR_AUTH_RES_AUTH_FAILED:
-			/* cause = illegal subscriber */
-			rej_cause = GSM48_REJECT_ILLEGAL_MS;
-			break;
-		case VLR_AUTH_RES_PROC_ERR:
-			/* cause = system failure */
-			rej_cause = GSM48_REJECT_NETWORK_FAILURE;
-			break;
-		default:
-			LOGPFSML(fi, LOGL_ERROR, "event without effect: %s\n",
-				 osmo_fsm_event_name(fi->fsm, event));
-			break;
-		}
-	} else
-		rej_cause = GSM48_REJECT_NETWORK_FAILURE;
+	if (!res || *res) {
+		lu_fsm_failure(fi, res? *res : GSM48_REJECT_NETWORK_FAILURE);
+		return;
+	}
 
-	lu_fsm_failure(fi, rej_cause);
+	/* Result == Pass */
+	vlr_loc_upd_post_auth(fi);
 }
 
 static void lu_fsm_wait_ciph(struct osmo_fsm_inst *fi, uint32_t event,
@@ -1489,14 +1463,20 @@ vlr_loc_update(struct osmo_fsm_inst *parent,
 	return fi;
 }
 
-/* Gracefully terminate an FSM created by vlr_loc_update() in case of external
- * timeout (i.e. from MSC). */
-void vlr_loc_update_conn_timeout(struct osmo_fsm_inst *fi)
+void vlr_loc_update_cancel(struct osmo_fsm_inst *fi,
+			   enum osmo_fsm_term_cause fsm_cause,
+			   uint8_t gsm48_cause)
 {
-	if (!fi || fi->state == VLR_ULA_S_DONE)
-		return;
-	LOGPFSM(fi, "Connection timed out\n");
-	lu_fsm_failure(fi, GSM48_REJECT_CONGESTION);
+	struct lu_fsm_priv *lfp;
+
+	OSMO_ASSERT(fi);
+	OSMO_ASSERT(fi->fsm == &vlr_lu_fsm);
+
+	lfp = fi->priv;
+	lfp->rej_cause = gsm48_cause;
+
+	if (fi->state != VLR_ULA_S_DONE)
+		lu_fsm_failure(fi, gsm48_cause);
 }
 
 void vlr_lu_fsm_init(void)