b2bua: new experimental module

2 files changed, 256 insertions, 0 deletions

diff --git a/modules/b2bua/b2bua.c b/modules/b2bua/b2bua.c
new file mode 100644
index 0000000..4eebff8
--- /dev/null
+++ b/modules/b2bua/b2bua.c
@@ -0,0 +1,246 @@
+/**
+ * @file b2bua.c Back-to-Back User-Agent (B2BUA) module
+ *
+ * Copyright (C) 2010 Creytiv.com
+ */
+#include <re.h>
+#include <baresip.h>
+
+
+/**
+ * @defgroup b2bua b2bua
+ *
+ * Back-to-Back User-Agent (B2BUA) module
+ *
+ * NOTE: This module is experimental.
+ *
+ * N session objects
+ * 1 session object has 2 call objects (left, right leg)
+ */
+
+
+struct session {
+	struct le le;
+	struct call *call_in, *call_out;
+};
+
+
+static struct list sessionl;
+static struct ua *ua_in, *ua_out;
+
+
+static struct call *other_call(struct session *sess, const struct call *call)
+{
+	if (sess->call_in == call) return sess->call_out;
+	if (sess->call_out == call) return sess->call_in;
+
+	return NULL;
+}
+
+
+static void destructor(void *arg)
+{
+	struct session *sess = arg;
+
+	debug("b2bua: session destroyed (in=%p, out=%p)\n",
+	      sess->call_in, sess->call_out);
+
+	list_unlink(&sess->le);
+	mem_deref(sess->call_out);
+	mem_deref(sess->call_in);
+}
+
+
+static void call_event_handler(struct call *call, enum call_event ev,
+			       const char *str, void *arg)
+{
+	struct session *sess = arg;
+	struct call *call2 = other_call(sess, call);
+
+	switch (ev) {
+
+	case CALL_EVENT_ESTABLISHED:
+		debug("b2bua: CALL_ESTABLISHED: peer_uri=%s\n",
+		      call_peeruri(call));
+		ua_answer(call_get_ua(call2), call2);
+		break;
+
+	case CALL_EVENT_CLOSED:
+		debug("b2bua: CALL_CLOSED: %s\n", str);
+
+		mem_ref(call2);
+
+		ua_hangup(call_get_ua(call2), call2, call_scode(call), "");
+		mem_deref(sess);
+		break;
+
+	default:
+		break;
+	}
+}
+
+
+static void call_dtmf_handler(struct call *call, char key, void *arg)
+{
+	struct session *sess = arg;
+
+	debug("b2bua: relaying DTMF event: key = '%c'\n", key ? key : '.');
+
+	call_send_digit(other_call(sess, call), key);
+}
+
+
+static int new_session(struct call *call)
+{
+	struct session *sess;
+	char a[64], b[64];
+	int err;
+
+	sess = mem_zalloc(sizeof(*sess), destructor);
+	if (!sess)
+		return ENOMEM;
+
+	sess->call_in = call;
+	err = ua_connect(ua_out, &sess->call_out, call_peeruri(call),
+			 call_localuri(call), NULL,
+			 call_has_video(call) ? VIDMODE_ON : VIDMODE_OFF);
+	if (err) {
+		warning("b2bua: ua_connect failed (%m)\n", err);
+		goto out;
+	}
+
+	re_snprintf(a, sizeof(a), "A-%x", sess);
+	re_snprintf(b, sizeof(b), "B-%x", sess);
+
+	/* connect the audio/video-bridge devices */
+	audio_set_devicename(call_audio(sess->call_in), a, b);
+	audio_set_devicename(call_audio(sess->call_out), b, a);
+	video_set_devicename(call_video(sess->call_in), a, b);
+	video_set_devicename(call_video(sess->call_out), b, a);
+
+	call_set_handlers(sess->call_in, call_event_handler,
+			  call_dtmf_handler, sess);
+	call_set_handlers(sess->call_out, call_event_handler,
+			  call_dtmf_handler, sess);
+
+	list_append(&sessionl, &sess->le, sess);
+
+ out:
+	if (err)
+		mem_deref(sess);
+
+	return err;
+}
+
+
+static void ua_event_handler(struct ua *ua, enum ua_event ev,
+			     struct call *call, const char *prm, void *arg)
+{
+	int err;
+	(void)prm;
+	(void)arg;
+
+	switch (ev) {
+
+	case UA_EVENT_CALL_INCOMING:
+		debug("b2bua: CALL_INCOMING: peer=%s  -->  local=%s\n",
+		      call_peeruri(call), call_localuri(call));
+
+		err = new_session(call);
+		if (err) {
+			ua_hangup(ua, call, 500, "Server Error");
+		}
+		break;
+
+	default:
+		break;
+	}
+}
+
+
+static int b2bua_status(struct re_printf *pf, void *arg)
+{
+	struct le *le;
+	int err = 0;
+	(void)arg;
+
+	err |= re_hprintf(pf, "B2BUA status:\n");
+	err |= re_hprintf(pf, "  inbound:  %s\n", ua_aor(ua_in));
+	err |= re_hprintf(pf, "  outbound: %s\n", ua_aor(ua_out));
+
+	err |= re_hprintf(pf, "sessions:\n");
+
+	for (le = sessionl.head; le; le = le->next) {
+
+		struct session *sess = le->data;
+
+		err |= re_hprintf(pf, "%-42s  --->  %42s\n",
+				  call_peeruri(sess->call_in),
+				  call_peeruri(sess->call_out));
+
+		err |= re_hprintf(pf, " %H\n", call_status, sess->call_in);
+		err |= re_hprintf(pf, " %H\n", call_status, sess->call_out);
+	}
+
+	return err;
+}
+
+
+static const struct cmd cmdv[] = {
+	{'b',       0, "b2bua status", b2bua_status },
+};
+
+
+static int module_init(void)
+{
+	int err;
+
+	ua_in  = uag_find_param("b2bua", "inbound");
+	ua_out = uag_find_param("b2bua", "outbound");
+
+	if (!ua_in) {
+		warning("b2bua: inbound UA not found\n");
+		return ENOENT;
+	}
+	if (!ua_out) {
+		warning("b2bua: outbound UA not found\n");
+		return ENOENT;
+	}
+
+	err = cmd_register(cmdv, ARRAY_SIZE(cmdv));
+	if (err)
+		return err;
+
+	err = uag_event_register(ua_event_handler, 0);
+	if (err)
+		return err;
+
+	debug("b2bua: module loaded\n");
+
+	return 0;
+}
+
+
+static int module_close(void)
+{
+	debug("b2bua: module closing..\n");
+
+	if (!list_isempty(&sessionl)) {
+
+		info("b2bua: flushing %u sessions\n", list_count(&sessionl));
+		list_flush(&sessionl);
+	}
+
+	uag_event_unregister(ua_event_handler);
+	cmd_unregister(cmdv);
+
+	return 0;
+}
+
+
+const struct mod_export DECL_EXPORTS(b2bua) = {
+	"b2bua",
+	"application",
+	module_init,
+	module_close
+};
diff --git a/modules/b2bua/module.mk b/modules/b2bua/module.mk
new file mode 100644
index 0000000..8afe230
--- /dev/null
+++ b/modules/b2bua/module.mk
@@ -0,0 +1,10 @@
+#
+# module.mk
+#
+# Copyright (C) 2010 Creytiv.com
+#
+
+MOD		:= b2bua
+$(MOD)_SRCS	+= b2bua.c
+
+include mk/mod.mk