call: Introduce a structure for representing a call

Right now a call has two legs, the initial one and the remote. In
general this will allow a SIP to SIP, SIP to MNCC and MNCC to MNCC
structure in the future.

src/Makefile.am

@@ -3,9 +3,10 @@ bin_PROGRAMS = osmo-sip-connector
 AM_CFLAGS=-Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOVTY_CFLAGS) $(SOFIASIP_CFLAGS)
 
 noinst_HEADERS = \
-	evpoll.h vty.h mncc_protocol.h app.h mncc.h sip.h
+	evpoll.h vty.h mncc_protocol.h app.h mncc.h sip.h call.h
 
 osmo_sip_connector_SOURCES = \
+		call.c \
 		sip.c \
 		mncc.c \
 		evpoll.c \

src/call.c

@@ -0,0 +1,24 @@
+/*
+ * (C) 2016 by Holger Hans Peter Freyther
+ *
+ * All Rights Reserved
+ *
+ * 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 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 "call.h"
+
+
+LLIST_HEAD(g_call_list);

src/call.h

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <osmocom/core/linuxlist.h>
+
+struct sip_agent;
+struct mncc_connection;
+
+struct call_leg;
+
+/**
+ * One instance of a call with two legs. The initial
+ * field will always be used by the entity that has
+ * launched the call.
+ */
+struct call {
+	struct llist_head entry;
+
+	struct call_leg *initial;
+	struct call_leg *remote;
+};
+
+enum {
+	CALL_TYPE_NONE,
+	CALL_TYPE_SIP,
+	CALL_TYPE_MNCC,
+};
+
+struct call_leg {
+	int type;
+};
+
+struct sip_call_leg {
+	struct call_leg base;
+
+	struct sip_agent *agent;
+};
+
+struct mncc_call_leg {
+	struct call_leg base;
+
+	struct mncc_connection *conn;
+};
+
+extern struct llist_head g_call_list;
+void calls_init(void);

src/main.c

@@ -25,6 +25,7 @@
 #include "logging.h"
 #include "mncc.h"
 #include "app.h"
+#include "call.h"
 
 #include <osmocom/core/application.h>
 #include <osmocom/core/utils.h>
@@ -147,6 +148,7 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 
+	calls_init();
 
 	/* marry sofia-sip to glib and glib to libosmocore */
 	loop = g_main_loop_new(NULL, FALSE);