[mgcp] Add some parsing for RSIP messages coming in

This will just call a callback and leave all the handling
to the application.
diff --git a/openbsc/src/mgcp/mgcp_protocol.c b/openbsc/src/mgcp/mgcp_protocol.c
index 7ad4e0a..b8c011e 100644
--- a/openbsc/src/mgcp/mgcp_protocol.c
+++ b/openbsc/src/mgcp/mgcp_protocol.c
@@ -98,6 +98,7 @@
 static struct msgb *handle_create_con(struct mgcp_config *cfg, struct msgb *msg);
 static struct msgb *handle_delete_con(struct mgcp_config *cfg, struct msgb *msg);
 static struct msgb *handle_modify_con(struct mgcp_config *cfg, struct msgb *msg);
+static struct msgb *handle_rsip(struct mgcp_config *cfg, struct msgb *msg);
 
 static int generate_call_id(struct mgcp_config *cfg)
 {
@@ -129,6 +130,9 @@
 	MGCP_REQUEST("CRCX", handle_create_con, "CreateConnection")
 	MGCP_REQUEST("DLCX", handle_delete_con, "DeleteConnection")
 	MGCP_REQUEST("MDCX", handle_modify_con, "ModifiyConnection")
+
+	/* SPEC extension */
+	MGCP_REQUEST("RSIP", handle_rsip, "ReSetInProgress")
 };
 
 static struct msgb *mgcp_msgb_alloc(void)
@@ -655,6 +659,13 @@
 	return create_response(error_code, "DLCX", trans_id);
 }
 
+static struct msgb *handle_rsip(struct mgcp_config *cfg, struct msgb *msg)
+{
+	if (cfg->reset_cb)
+		cfg->reset_cb(cfg);
+	return NULL;
+}
+
 struct mgcp_config *mgcp_config_alloc(void)
 {
 	struct mgcp_config *cfg;