mncc: Dispatch setup and issue rtp create in response then continue

The code is not tested and might be broken. Parse the setup request
of a MO call, create a new "call" with a MNCC leg and then issue the
call to create a RTP socket. Once this has been done, release the call
as the code to open a second leg has not been written yet.

src/call.c

@@ -23,8 +23,10 @@
 
 #include <talloc.h>
 
+extern void *tall_mncc_ctx;
 
 LLIST_HEAD(g_call_list);
+static uint32_t last_call_id = 5000;
 
 void calls_init(void)
 {}
@@ -48,3 +50,26 @@ void call_leg_release(struct call *call, struct call_leg *leg)
 		talloc_free(call);
 	}
 }
+
+struct call *sip_call_mncc_create(void)
+{
+	struct call *call;
+
+	call = talloc_zero(tall_mncc_ctx, struct call);
+	if (!call) {
+		LOGP(DCALL, LOGL_ERROR, "Failed to allocate memory for call\n");
+		return NULL;
+	}
+	call->id = ++last_call_id;
+
+	call->initial = (struct call_leg *) talloc_zero(call, struct mncc_call_leg);
+	if (!call->initial) {
+		LOGP(DCALL, LOGL_ERROR, "Failed to allocate MNCC leg\n");
+		talloc_free(call);
+		return NULL;
+	}
+
+	call->initial->type = CALL_TYPE_MNCC;
+	llist_add(&call->entry, &g_call_list);
+	return call;
+}

src/call.h

@@ -2,6 +2,8 @@
 
 #include <osmocom/core/linuxlist.h>
 
+#include "mncc_protocol.h"
+
 struct sip_agent;
 struct mncc_connection;
 
@@ -42,9 +44,18 @@ struct sip_call_leg {
 	struct sip_agent *agent;
 };
 
+enum mncc_cc_state {
+	MNCC_CC_INITIAL,
+};
+
 struct mncc_call_leg {
 	struct call_leg base;
 
+	enum mncc_cc_state state;
+	uint32_t callref;
+	struct gsm_mncc_number called;
+	struct gsm_mncc_number calling;
+
 	struct mncc_connection *conn;
 };
 
@@ -53,3 +64,6 @@ void calls_init(void);
 
 
 void call_leg_release(struct call *call, struct call_leg *leg);
+
+
+struct call *sip_call_mncc_create(void);

src/mncc.c

@@ -22,8 +22,10 @@
 #include "mncc_protocol.h"
 #include "app.h"
 #include "logging.h"
+#include "call.h"
 
 #include <osmocom/core/socket.h>
+#include <osmocom/core/utils.h>
 
 #include <sys/socket.h>
 #include <sys/un.h>
@@ -31,6 +33,88 @@
 #include <errno.h>
 #include <unistd.h>
 
+static void close_connection(struct mncc_connection *conn);
+
+
+static struct mncc_call_leg *mncc_find_leg(uint32_t callref, struct call **out_call)
+{
+	struct call *call;
+
+	llist_for_each_entry(call, &g_call_list, entry) {
+		if (call->initial && call->initial->type == CALL_TYPE_MNCC) {
+			struct mncc_call_leg *leg = (struct mncc_call_leg *) call->initial;
+			if (leg->callref == callref) {
+				*out_call = call;
+				return leg;
+			}
+		}
+		if (call->remote && call->remote->type == CALL_TYPE_MNCC) {
+			struct mncc_call_leg *leg = (struct mncc_call_leg *) call->remote;
+			if (leg->callref == callref) {
+				*out_call = call;
+				return leg;
+			}
+		}
+	}
+
+	*out_call = NULL;
+	return NULL;
+}
+
+static void mncc_send(struct mncc_connection *conn, uint32_t msg_type, uint32_t callref)
+{
+	int rc;
+	struct gsm_mncc mncc = { 0, };
+
+	mncc.msg_type = msg_type;
+	mncc.callref = callref;
+
+	/*
+	 * TODO: we need to put cause in here for release or such? shall we return a
+	 * static struct?
+	 */
+	rc = write(conn->fd.fd, &mncc, sizeof(mncc));
+	if (rc != sizeof(mncc)) {
+		LOGP(DMNCC, LOGL_ERROR, "Failed to send message call(%u)\n", callref);
+		close_connection(conn);
+	}
+}
+
+static void mncc_rtp_send(struct mncc_connection *conn, uint32_t msg_type, uint32_t callref)
+{
+	int rc;
+	struct gsm_mncc_rtp mncc = { 0, };
+
+	mncc.msg_type = msg_type;
+	mncc.callref = callref;
+
+	rc = write(conn->fd.fd, &mncc, sizeof(mncc));
+	if (rc != sizeof(mncc)) {
+		LOGP(DMNCC, LOGL_ERROR, "Failed to send message call(%u)\n", callref);
+		close_connection(conn);
+	}
+}
+
+
+static void mncc_call_leg_release(struct call *call, struct call_leg *_leg)
+{
+	struct mncc_call_leg *leg;
+
+	OSMO_ASSERT(_leg->type == CALL_TYPE_MNCC);
+	leg = (struct mncc_call_leg *) _leg;
+
+	/* drop it directly, if not connected */
+	if (leg->conn->state != MNCC_READY)
+		return call_leg_release(call, _leg);
+
+	switch (leg->state) {
+	case MNCC_CC_INITIAL:
+		mncc_send(leg->conn, MNCC_REJ_REQ, leg->callref);
+		call_leg_release(call, _leg);
+		break;
+	}
+}
+
 static void close_connection(struct mncc_connection *conn)
 {
 	osmo_fd_unregister(&conn->fd);
@@ -41,6 +125,79 @@ static void close_connection(struct mncc_connection *conn)
 		conn->on_disconnect(conn);
 }
 
+static void check_rtp_create(struct mncc_connection *conn, char *buf, int rc)
+{
+	struct gsm_mncc_rtp *rtp;
+	struct call *call;
+	struct mncc_call_leg *leg;
+
+	if (rc < sizeof(*rtp)) {
+		LOGP(DMNCC, LOGL_ERROR, "gsm_mncc_rtp of wrong size %d < %d\n",
+			rc, sizeof(*rtp));
+		return close_connection(conn);
+	}
+
+	rtp = (struct gsm_mncc_rtp *) buf;
+	leg = mncc_find_leg(rtp->callref, &call);
+	if (!leg) {
+		LOGP(DMNCC, LOGL_ERROR, "call(%u) can not be found\n", rtp->callref);
+		return mncc_send(conn, MNCC_REJ_REQ, rtp->callref);
+	}
+
+	/* TODO.. now we can continue with the call */
+	mncc_send(leg->conn, MNCC_REJ_REQ, leg->callref);
+	call_leg_release(call, &leg->base);
+}
+
+static void check_setup(struct mncc_connection *conn, char *buf, int rc)
+{
+	struct gsm_mncc *data;
+	struct call *call;
+	struct mncc_call_leg *leg;
+
+	if (rc != sizeof(*data)) {
+		LOGP(DMNCC, LOGL_ERROR, "gsm_mncc of wrong size %d vs. %d\n",
+			rc, sizeof(*data));
+		return close_connection(conn);
+	}
+
+	data = (struct gsm_mncc *) buf;
+
+	/* screen arguments */
+	if ((data->fields & MNCC_F_CALLED) == 0) {
+		LOGP(DMNCC, LOGL_ERROR,
+			"MNCC call(%u) without called addr fields(%u)\n",
+			data->callref, data->fields);
+		return mncc_send(conn, MNCC_REJ_REQ, data->callref);
+	}
+	if ((data->fields & MNCC_F_CALLING) == 0) {
+		LOGP(DMNCC, LOGL_ERROR,
+			"MNCC call(%u) without calling addr fields(%u)\n",
+			data->callref, data->fields);
+		return mncc_send(conn, MNCC_REJ_REQ, data->callref);
+	}
+
+	/* TODO.. bearer caps and better audio handling */
+
+	/* Create an RTP port and then allocate a call */
+	call = sip_call_mncc_create();
+	if (!call) {
+		LOGP(DMNCC, LOGL_ERROR,
+			"MNCC call(%u) failed to allocate call\n", data->callref);
+		return mncc_send(conn, MNCC_REJ_REQ, data->callref);
+	}
+
+	leg = (struct mncc_call_leg *) call->initial;
+	leg->base.release_call = mncc_call_leg_release;
+	leg->callref = data->callref;
+	leg->conn = conn;
+	leg->state = MNCC_CC_INITIAL;
+	memcpy(&leg->called, &data->called, sizeof(leg->called));
+	memcpy(&leg->calling, &data->calling, sizeof(leg->calling));
+
+	mncc_rtp_send(conn, MNCC_RTP_CREATE, data->callref);
+}
+
 static void check_hello(struct mncc_connection *conn, char *buf, int rc)
 {
 	struct gsm_mncc_hello *hello;
@@ -105,6 +262,12 @@ static int mncc_data(struct osmo_fd *fd, unsigned int what)
 	case MNCC_SOCKET_HELLO:
 		check_hello(conn, buf, rc);
 		break;
+	case MNCC_SETUP_IND:
+		check_setup(conn, buf, rc);
+		break;
+	case MNCC_RTP_CREATE:
+		check_rtp_create(conn, buf, rc);
+		break;
 	default:
 		LOGP(DMNCC, LOGL_ERROR, "Unhandled message type %d/0x%x\n",
 			msg_type, msg_type);

src/mncc.h

@@ -3,6 +3,8 @@
 #include <osmocom/core/select.h>
 #include <osmocom/core/timer.h>
 
+#include <stdint.h>
+
 struct app_config;
 
 enum {
@@ -18,6 +20,7 @@ struct mncc_connection {
 
 	struct osmo_timer_list reconnect;
 
+	uint32_t last_callref;
 
 	/* callback for application logic */
 	void (*on_disconnect)(struct mncc_connection *);