mgcp: make sure all endpoints are closed on startup

If the MSC is crashing and restarting, it may leave some endpoints
open. The endpoints can not be re-used until they are deleted
(DLCX). This patch sends a DLCX to all possible endpoints (usually
this is in a countable range) in order to clear possible open
endpoints from a previous run

Change-Id: I9de2f67ffe08b2d76574ef4470c7a9767ca74702

include/openbsc/msc_ifaces.h

@@ -56,3 +56,4 @@ int msc_tx_common_id(struct gsm_subscriber_connection *conn);
 int msc_call_assignment(struct gsm_trans *trans);
 int msc_call_bridge(struct gsm_trans *trans1, struct gsm_trans *trans2);
 void msc_call_release(struct gsm_trans *trans);
+void msc_call_release_all(struct mgcpgw_client *mgcp);

src/libmgcp/mgcpgw_client.c

@@ -402,7 +402,8 @@ int mgcpgw_client_connect(struct mgcpgw_client *mgcp)
 
 	mgcp->remote_addr = htonl(addr.sin_addr.s_addr);
 
-	osmo_wqueue_init(wq, 10);
+	osmo_wqueue_init(wq, (mgcp->actual.last_endpoint - mgcp->actual.first_endpoint) + 10);
+
 	wq->bfd.when = BSC_FD_READ;
 	wq->bfd.data = mgcp;
 	wq->read_cb = mgcp_do_read;

src/libmsc/msc_ifaces.c

@@ -344,3 +344,21 @@ void msc_call_release(struct gsm_trans *trans)
 	/* Release endpoint id */
 	mgcpgw_client_release_endpoint(conn->iu.mgcp_rtp_endpoint, mgcp);
 }
+
+void msc_call_release_all(struct mgcpgw_client *mgcp)
+{
+	struct msgb *msg;
+	unsigned int i;
+
+	uint16_t first_endpoint = mgcp->actual.first_endpoint;
+	uint16_t last_endpoint = mgcp->actual.last_endpoint;
+
+	for (i = first_endpoint; i < last_endpoint; i++) {
+		msg = mgcp_msg_dlcx(mgcp, i);
+		if (mgcpgw_client_tx(mgcp, msg, NULL, NULL))
+			LOGP(DMGCP, LOGL_ERROR,
+			     "Failed to send DLCX message for endpoint %u\n", i);
+
+		mgcpgw_client_release_endpoint(i, mgcp);
+	}
+}

src/osmo-msc/msc_main.c

@@ -495,6 +495,10 @@ TODO: we probably want some of the _net_ ctrl commands from bsc_base_ctrl_cmds_i
 		return 7;
 	}
 
+	/* Make sure all mgcp endpoints are cleared */
+	msc_call_release_all(msc_network->mgcpgw.client);
+
+
 	/* Set up A-Interface */
 	/* TODO: implement A-Interface and remove above legacy stuff. */