libcommon-cs: genralize a interface reset fsm

The AoIP standard also describes an MSC->BSC reset procedure. We
currently do not implement it. However, the fsm that is used to
issue the reset request from the bsc side is not generalized. This
patch generalizes the code in order to be able to use the same
code on the MSC side to perform a reset procedure from there.

Change-Id: I65e20bebb126ba35122ca3a545393d18fcadf5ad

4 files changed, 63 insertions, 9 deletions

diff --git a/include/openbsc/Makefile.am b/include/openbsc/Makefile.am
index b33bdee02..e5377a077 100644
--- a/include/openbsc/Makefile.am
+++ b/include/openbsc/Makefile.am
@@ -67,7 +67,7 @@ noinst_HEADERS = \
 	openbscdefines.h \
 	osmo_bsc.h \
 	osmo_bsc_grace.h \
-	osmo_bsc_reset.h \
+	a_reset.h \
 	osmo_bsc_rf.h \
 	osmo_msc.h \
 	osmo_bsc_sigtran.h \
diff --git a/include/openbsc/a_reset.h b/include/openbsc/a_reset.h
new file mode 100644
index 000000000..124cf13f1
--- /dev/null
+++ b/include/openbsc/a_reset.h
@@ -0,0 +1,60 @@
+/* (C) 2017 by sysmocom s.f.m.c. GmbH
+ * All Rights Reserved
+ *
+ * Author: Philipp Maier
+ *
+ * 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/>.
+ *
+ */
+
+#pragma once
+
+
+
+/* Reset context data (callbacks, state machine etc...) */
+struct a_reset_ctx {
+
+	/* FSM instance, which handles the reset procedure */
+	struct osmo_fsm_inst *fsm;
+
+	/* Connection failure counter. When this counter
+	 * reaches a certain threshold, the reset procedure
+	 * will be triggered */
+	int conn_loss_counter;
+
+	/* A human readable name to display in the logs */
+	char name[256];
+
+	/* Callback function to be called when a connection
+	 * failure is detected and a rest must occur */
+	void (*cb)(void *priv);
+
+	/* Privated data for the callback function */
+	void *priv;
+};
+
+/* Create and start state machine which handles the reset/reset-ack procedure */
+void a_reset_start(struct a_reset_ctx *reset);
+
+/* Confirm that we sucessfully received a reset acknowlege message */
+void a_reset_ack_confirm(struct a_reset_ctx *reset);
+
+/* Report a failed connection */
+void a_reset_conn_fail(struct a_reset_ctx *reset);
+
+/* Report a successful connection */
+void a_reset_conn_success(struct a_reset_ctx *reset);
+
+/* Check if we have a connection to a specified msc */
+bool a_reset_conn_ready(struct a_reset_ctx *reset);
diff --git a/include/openbsc/bsc_msc.h b/include/openbsc/bsc_msc.h
index b80729c3a..a7c881b84 100644
--- a/include/openbsc/bsc_msc.h
+++ b/include/openbsc/bsc_msc.h
@@ -25,6 +25,7 @@
 #include <osmocom/core/write_queue.h>
 #include <osmocom/core/timer.h>
 #include <osmocom/sigtran/sccp_sap.h>
+#include <openbsc/a_reset.h>
 
 #include <netinet/in.h>
 
@@ -60,8 +61,7 @@ struct bsc_msc_connection {
 	struct osmo_sccp_user *sccp_user;
 	struct osmo_sccp_addr g_calling_addr;
 	struct osmo_sccp_addr g_called_addr;
-	struct osmo_fsm_inst *fsm_reset;
-	unsigned int msc_conn_loss_count;
+	struct a_reset_ctx reset;
 
 	int conn_id_counter;
 };
diff --git a/include/openbsc/osmo_bsc_sigtran.h b/include/openbsc/osmo_bsc_sigtran.h
index 92d8ba64e..caeea6092 100644
--- a/include/openbsc/osmo_bsc_sigtran.h
+++ b/include/openbsc/osmo_bsc_sigtran.h
@@ -38,11 +38,5 @@ int osmo_bsc_sigtran_send(struct osmo_bsc_sccp_con *conn, struct msgb *msg);
  * locally, when a connection is closed by the MSC */
 int osmo_bsc_sigtran_del_conn(struct osmo_bsc_sccp_con *sccp);
 
-/* Send reset to MSC */
-void osmo_bsc_sigtran_tx_reset(struct bsc_msc_data *msc);
-
-/* close all open connections */
-void osmo_bsc_sigtran_reset(struct bsc_msc_data *msc);
-
 /* Initalize osmo sigtran backhaul */
 int osmo_bsc_sigtran_init(struct llist_head *mscs);