1 files changed, 269 insertions, 0 deletions
diff --git a/openbsc/src/libmsc/subscr_conn.c b/openbsc/src/libmsc/subscr_conn.c
new file mode 100644
index 000000000..91ffe4069
--- /dev/null
+++ b/openbsc/src/libmsc/subscr_conn.c
@@ -0,0 +1,269 @@
+/* MSC subscriber connection implementation */
+
+/*
+ * (C) 2016 by sysmocom s.m.f.c. <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * Author: Neels Hofmeyr
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <osmocom/core/logging.h>
+#include <osmocom/core/fsm.h>
+
+#include <openbsc/osmo_msc.h>
+#include <openbsc/vlr.h>
+#include <openbsc/debug.h>
+#include <openbsc/transaction.h>
+
+static const struct value_string subscr_conn_fsm_event_names[] = {
+	OSMO_VALUE_STRING(SUBSCR_CONN_E_INVALID),
+	OSMO_VALUE_STRING(SUBSCR_CONN_E_ACCEPTED),
+	OSMO_VALUE_STRING(SUBSCR_CONN_E_BUMP),
+	OSMO_VALUE_STRING(SUBSCR_CONN_E_MO_CLOSE),
+	OSMO_VALUE_STRING(SUBSCR_CONN_E_CN_CLOSE),
+	OSMO_VALUE_STRING(SUBSCR_CONN_E_CLOSE_CONF),
+	{ 0, NULL }
+};
+
+const struct value_string subscr_conn_from_names[] = {
+	OSMO_VALUE_STRING(SUBSCR_CONN_FROM_INVALID),
+	OSMO_VALUE_STRING(SUBSCR_CONN_FROM_LU),
+	OSMO_VALUE_STRING(SUBSCR_CONN_FROM_CM_SERVICE_REQ),
+	OSMO_VALUE_STRING(SUBSCR_CONN_FROM_PAGING_RESP),
+	{ 0, NULL }
+};
+
+static void paging_resp(struct gsm_subscriber_connection *conn,
+			       enum gsm_paging_event pe)
+{
+	subscr_paging_dispatch(GSM_HOOK_RR_PAGING, pe, NULL, conn, conn->subscr);
+}
+
+void subscr_conn_fsm_new(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	struct gsm_subscriber_connection *conn = fi->priv;
+	enum subscr_conn_from from = SUBSCR_CONN_FROM_INVALID;
+	enum gsm_paging_event pe;
+
+	if (data) {
+		from = *(enum subscr_conn_from*)data;
+		LOGPFSM(fi, "%s\n", subscr_conn_from_name(from));
+	}
+
+	/* If accepted, transition the state, all other cases mean failure. */
+	switch (event) {
+	case SUBSCR_CONN_E_ACCEPTED:
+		osmo_fsm_inst_state_chg(fi, SUBSCR_CONN_S_ACCEPTED, 0, 0);
+		break;
+
+	case SUBSCR_CONN_E_MO_CLOSE:
+	case SUBSCR_CONN_E_CN_CLOSE:
+	case SUBSCR_CONN_E_CLOSE_CONF:
+		break;
+
+	default:
+		LOGPFSM(fi, "Unexpected event: %d %s\n",
+			event, osmo_fsm_event_name(fi->fsm, event));
+		break;
+	}
+
+	/* if appropriate, signal paging success or failure */
+	if (from == SUBSCR_CONN_FROM_PAGING_RESP) {
+		pe = (fi->state == SUBSCR_CONN_S_ACCEPTED)?
+			GSM_PAGING_SUCCEEDED : GSM_PAGING_EXPIRED;
+		paging_resp(conn, pe);
+	}
+
+	/* On failure, discard the conn */
+	if (fi->state != SUBSCR_CONN_S_ACCEPTED) {
+		/* TODO: on MO_CLOSE or CN_CLOSE, first go to RELEASING and
+		 * await BSC confirmation? */
+		osmo_fsm_inst_state_chg(fi, SUBSCR_CONN_S_RELEASED, 0, 0);
+		return;
+	}
+
+	/* On success, handle pending requests and/or close conn */
+
+	if (from == SUBSCR_CONN_FROM_CM_SERVICE_REQ) {
+		conn->received_cm_service_request = true;
+		LOGPFSM(fi, "received_cm_service_request = true\n");
+	}
+
+	osmo_fsm_inst_dispatch(fi, SUBSCR_CONN_E_BUMP, data);
+}
+
+#if 0
+	case SUBSCR_CONN_E_PARQ_SUCCESS:
+		osmo_fsm_inst_state_chg(fi, SUBSCR_CONN_S_ACCEPTED, 0, 0);
+		accept_conn = true;
+		/* fall through */
+	case SUBSCR_CONN_E_PARQ_FAILURE:
+		parq_type = data ? *(enum vlr_parq_type*)data : VLR_PR_ARQ_T_INVALID;
+		switch (parq_type) {
+
+		case VLR_PR_ARQ_T_CM_SERV_REQ:
+			accept_conn = handle_cm_serv_result(fi, accept_conn);
+			break;
+
+		case VLR_PR_ARQ_T_PAGING_RESP:
+			accept_conn = handle_paging_result(fi, accept_conn);
+			break;
+
+		default:
+			LOGPFSML(fi, LOGL_ERROR,
+				 "Invalid VLR Process Access Request type"
+				 " %d\n", parq_type);
+			accept_conn = false;
+			break;
+		}
+		break;
+#endif
+
+static void subscr_conn_fsm_bump(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	struct gsm_subscriber_connection *conn = fi->priv;
+
+	if (conn->silent_call)
+		return;
+
+	if (conn->received_cm_service_request)
+		return;
+
+	/* is this needed? */
+	if (conn->subscr && !llist_empty(&conn->subscr->requests))
+		return;
+
+	if (trans_has_conn(conn))
+		return;
+
+	osmo_fsm_inst_state_chg(fi, SUBSCR_CONN_S_RELEASED, 0, 0);
+}
+
+static void subscr_conn_fsm_accepted(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	switch (event) {
+	case SUBSCR_CONN_E_BUMP:
+		subscr_conn_fsm_bump(fi, event, data);
+		return;
+
+	default:
+		break;
+	}
+	/* Whatever unexpected happens in the accepted state, it means release.
+	 * Even if an unexpected event is passed, the safest thing to do is
+	 * discard the conn. We don't expect another SUBSCR_CONN_E_ACCEPTED. */
+	osmo_fsm_inst_state_chg(fi, SUBSCR_CONN_S_RELEASED, 0, 0);
+}
+
+static void subscr_conn_fsm_release(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+	struct gsm_subscriber_connection *conn = fi->priv;
+	if (!conn)
+		return;
+
+	/* temporary hack, see owned_by_msc */
+	if (!conn->owned_by_msc) {
+		DEBUGP(DMM, "%s leaving bsc_subscr_con_free() to bsc_api.c, owned_by_msc = false\n",
+		       subscr_name(conn->subscr));
+		return;
+	}
+
+	DEBUGP(DMM, "%s calling bsc_subscr_con_free(), owned_by_msc = true\n",
+	       subscr_name(conn->subscr));
+	gsm0808_clear(conn);
+	bsc_subscr_con_free(conn);
+}
+
+#define S(x)	(1 << (x))
+
+static const struct osmo_fsm_state subscr_conn_fsm_states[] = {
+	[SUBSCR_CONN_S_NEW] = {
+		.name = OSMO_STRINGIFY(SUBSCR_CONN_S_NEW),
+		.in_event_mask = S(SUBSCR_CONN_E_ACCEPTED) |
+				 S(SUBSCR_CONN_E_MO_CLOSE) |
+				 S(SUBSCR_CONN_E_CN_CLOSE) |
+				 S(SUBSCR_CONN_E_CLOSE_CONF),
+		.out_state_mask = S(SUBSCR_CONN_S_ACCEPTED) |
+				  S(SUBSCR_CONN_S_RELEASED),
+		.action = subscr_conn_fsm_new,
+	},
+	[SUBSCR_CONN_S_ACCEPTED] = {
+		.name = OSMO_STRINGIFY(SUBSCR_CONN_S_ACCEPTED),
+		/* allow everything to release for any odd behavior */
+		.in_event_mask = S(SUBSCR_CONN_E_ACCEPTED) |
+				 S(SUBSCR_CONN_E_BUMP) |
+				 S(SUBSCR_CONN_E_MO_CLOSE) |
+				 S(SUBSCR_CONN_E_CN_CLOSE) |
+				 S(SUBSCR_CONN_E_CLOSE_CONF),
+		.out_state_mask = S(SUBSCR_CONN_S_RELEASED),
+		.action = subscr_conn_fsm_accepted,
+	},
+	[SUBSCR_CONN_S_RELEASED] = {
+		.name = OSMO_STRINGIFY(SUBSCR_CONN_S_RELEASED),
+		.onenter = subscr_conn_fsm_release,
+	},
+};
+
+static struct osmo_fsm subscr_conn_fsm = {
+	.name = "Subscr_Conn",
+	.states = subscr_conn_fsm_states,
+	.num_states = ARRAY_SIZE(subscr_conn_fsm_states),
+	.allstate_event_mask = 0,
+	.allstate_action = NULL,
+	.log_subsys = DVLR,
+	.event_names = subscr_conn_fsm_event_names,
+};
+
+int msc_create_conn_fsm(struct gsm_subscriber_connection *conn, const char *id)
+{
+	struct osmo_fsm_inst *fi;
+	OSMO_ASSERT(conn);
+
+	if (conn->conn_fsm) {
+		LOGP(DMM, LOGL_ERROR,
+		     "%s: Error: connection already in use\n", id);
+		return -EINVAL;
+	}
+
+	fi = osmo_fsm_inst_alloc(&subscr_conn_fsm, conn, conn, LOGL_DEBUG, id);
+
+	if (!fi) {
+		LOGP(DMM, LOGL_ERROR,
+		     "%s: Failed to allocate subscr conn master FSM\n", id);
+		return -ENOMEM;
+	}
+	conn->conn_fsm = fi;
+	return 0;
+}
+
+bool msc_subscr_conn_is_accepted(struct gsm_subscriber_connection *conn)
+{
+	if (!conn)
+		return false;
+	if (!conn->subscr)
+		return false;
+	if (!conn->conn_fsm)
+		return false;
+	if (conn->conn_fsm->state != SUBSCR_CONN_S_ACCEPTED)
+		return false;
+	return true;
+}
+
+void msc_subscr_conn_init(void)
+{
+	osmo_fsm_register(&subscr_conn_fsm);
+}