1 files changed, 581 insertions, 0 deletions

diff --git a/spa/plugins/bluez5/midi-server.c b/spa/plugins/bluez5/midi-server.c
new file mode 100644
index 0000000..a1b2682
--- /dev/null
+++ b/spa/plugins/bluez5/midi-server.c
@@ -0,0 +1,581 @@
+/* Spa Bluez5 midi
+ *
+ * Copyright © 2022 Pauli Virtanen
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <errno.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include <spa/utils/defs.h>
+#include <spa/utils/string.h>
+#include <spa/utils/result.h>
+
+#include "midi.h"
+
+#include "bluez5-interface-gen.h"
+#include "dbus-monitor.h"
+
+#undef SPA_LOG_TOPIC_DEFAULT
+#define SPA_LOG_TOPIC_DEFAULT (&impl->log_topic)
+
+#define MIDI_SERVER_PATH	"/midiserver%u"
+#define MIDI_SERVICE_PATH	"/midiserver%u/service"
+#define MIDI_CHR_PATH		"/midiserver%u/service/chr"
+#define MIDI_DSC_PATH		"/midiserver%u/service/chr/dsc"
+
+#define BLE_DEFAULT_MTU		23
+
+struct impl
+{
+	struct spa_bt_midi_server this;
+
+	struct spa_log_topic log_topic;
+	struct spa_log *log;
+
+	const struct spa_bt_midi_server_cb *cb;
+
+	GDBusConnection *conn;
+	struct dbus_monitor monitor;
+	GDBusObjectManagerServer *manager;
+
+	Bluez5GattCharacteristic1 *chr;
+
+	void *user_data;
+
+	uint32_t server_id;
+
+	unsigned int write_acquired:1;
+	unsigned int notify_acquired:1;
+};
+
+struct _MidiServerManagerProxy
+{
+	Bluez5GattManager1Proxy parent_instance;
+
+	GCancellable *register_call;
+	unsigned int registered:1;
+};
+
+G_DECLARE_FINAL_TYPE(MidiServerManagerProxy, midi_server_manager_proxy, MIDI_SERVER,
+		MANAGER_PROXY, Bluez5GattManager1Proxy)
+G_DEFINE_TYPE(MidiServerManagerProxy, midi_server_manager_proxy, BLUEZ5_TYPE_GATT_MANAGER1_PROXY)
+#define MIDI_SERVER_TYPE_MANAGER_PROXY	(midi_server_manager_proxy_get_type())
+
+
+/*
+ * Characteristic user descriptor: not in BLE MIDI standard, but we
+ * put a device name here in case we have multiple MIDI endpoints.
+ */
+
+static gboolean dsc_handle_read_value(Bluez5GattDescriptor1 *iface, GDBusMethodInvocation *invocation,
+		GVariant *arg_options, gpointer user_data)
+{
+	struct impl *impl = user_data;
+	const char *description = NULL;
+	uint16_t offset = 0;
+	int len;
+
+	g_variant_lookup(arg_options, "offset", "q", &offset);
+
+	if (impl->cb->get_description)
+		description = impl->cb->get_description(impl->user_data);
+	if (!description)
+		description = "";
+
+	len = strlen(description);
+	if (offset > len) {
+		g_dbus_method_invocation_return_dbus_error(invocation,
+				"org.freedesktop.DBus.Error.InvalidArgs",
+				"Invalid arguments");
+		return TRUE;
+	}
+
+	bluez5_gatt_descriptor1_complete_read_value(iface,
+			invocation, description + offset);
+	return TRUE;
+}
+
+static int export_dsc(struct impl *impl)
+{
+	static const char * const flags[] = { "encrypt-read", NULL };
+	GDBusObjectSkeleton *skeleton = NULL;
+	Bluez5GattDescriptor1 *iface = NULL;
+	int res = -ENOMEM;
+	char path[128];
+
+	iface = bluez5_gatt_descriptor1_skeleton_new();
+	if (!iface)
+		goto done;
+
+	spa_scnprintf(path, sizeof(path), MIDI_DSC_PATH, impl->server_id);
+	skeleton = g_dbus_object_skeleton_new(path);
+	if (!skeleton)
+		goto done;
+	g_dbus_object_skeleton_add_interface(skeleton, G_DBUS_INTERFACE_SKELETON(iface));
+
+	bluez5_gatt_descriptor1_set_uuid(iface, BT_GATT_CHARACTERISTIC_USER_DESCRIPTION_UUID);
+	spa_scnprintf(path, sizeof(path), MIDI_CHR_PATH, impl->server_id);
+	bluez5_gatt_descriptor1_set_characteristic(iface, path);
+	bluez5_gatt_descriptor1_set_flags(iface, flags);
+
+	g_signal_connect(iface, "handle-read-value", G_CALLBACK(dsc_handle_read_value), impl);
+
+	g_dbus_object_manager_server_export(impl->manager, skeleton);
+
+	spa_log_debug(impl->log, "MIDI GATT Descriptor exported, path=%s",
+			g_dbus_object_get_object_path(G_DBUS_OBJECT(skeleton)));
+
+	res = 0;
+
+done:
+	g_clear_object(&iface);
+	g_clear_object(&skeleton);
+	return res;
+}
+
+
+/*
+ * MIDI characteristic
+ */
+
+static gboolean chr_handle_read_value(Bluez5GattCharacteristic1 *iface,
+		GDBusMethodInvocation *invocation, GVariant *arg_options,
+		gpointer user_data)
+{
+	/* BLE MIDI-1.0: returns empty value */
+	bluez5_gatt_characteristic1_complete_read_value(iface, invocation, "");
+	return TRUE;
+}
+
+static void chr_change_acquired(struct impl *impl, bool write, bool enabled)
+{
+	if (write) {
+		impl->write_acquired = enabled;
+		bluez5_gatt_characteristic1_set_write_acquired(impl->chr, enabled);
+	} else {
+		impl->notify_acquired = enabled;
+		bluez5_gatt_characteristic1_set_notify_acquired(impl->chr, enabled);
+	}
+}
+
+static int create_socketpair(int fds[2])
+{
+	if (socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_NONBLOCK | SOCK_CLOEXEC, 0, fds) < 0)
+		return -errno;
+	return 0;
+}
+
+static gboolean chr_handle_acquire(Bluez5GattCharacteristic1 *object,
+		GDBusMethodInvocation *invocation,
+		GUnixFDList *dummy, GVariant *arg_options,
+		bool write, gpointer user_data)
+{
+	struct impl *impl = user_data;
+	const char *err_msg = "Failed";
+	uint16_t mtu = BLE_DEFAULT_MTU;
+	gint fds[2] = {-1, -1};
+	int res;
+	GUnixFDList *fd_list = NULL;
+	GVariant *fd_handle = NULL;
+	GError *err = NULL;
+
+	if ((write && (impl->cb->acquire_write == NULL)) ||
+			(!write && (impl->cb->acquire_notify == NULL))) {
+		err_msg = "Not supported";
+		goto fail;
+	}
+	if ((write && impl->write_acquired) ||
+			(!write && impl->notify_acquired)) {
+		err_msg = "Already acquired";
+		goto fail;
+	}
+
+	g_variant_lookup(arg_options, "mtu", "q", &mtu);
+
+	if (create_socketpair(fds) < 0) {
+		err_msg = "Socketpair creation failed";
+		goto fail;
+	}
+
+	if (write)
+		res = impl->cb->acquire_write(impl->user_data, fds[0], mtu);
+	else
+		res = impl->cb->acquire_notify(impl->user_data, fds[0], mtu);
+	if (res < 0) {
+		err_msg = "Acquiring failed";
+		goto fail;
+	}
+	fds[0] = -1;
+
+	fd_handle = g_variant_new_handle(0);
+	fd_list = g_unix_fd_list_new_from_array(&fds[1], 1);
+	fds[1] = -1;
+
+	chr_change_acquired(impl, write, true);
+
+	if (write) {
+		bluez5_gatt_characteristic1_complete_acquire_write(
+			object, invocation, fd_list, fd_handle, mtu);
+	} else {
+		bluez5_gatt_characteristic1_complete_acquire_notify(
+			object, invocation, fd_list, fd_handle, mtu);
+	}
+
+	g_clear_object(&fd_list);
+	return TRUE;
+
+fail:
+	if (fds[0] >= 0)
+		close(fds[0]);
+	if (fds[1] >= 0)
+		close(fds[1]);
+
+	if (err)
+		g_error_free(err);
+	g_clear_pointer(&fd_handle, g_variant_unref);
+	g_clear_object(&fd_list);
+	g_dbus_method_invocation_return_dbus_error(invocation,
+			"org.freedesktop.DBus.Error.Failed", err_msg);
+	return TRUE;
+
+}
+
+static gboolean chr_handle_acquire_write(Bluez5GattCharacteristic1 *object,
+		GDBusMethodInvocation *invocation,
+		GUnixFDList *fd_list, GVariant *arg_options,
+		gpointer user_data)
+{
+	return chr_handle_acquire(object, invocation, fd_list, arg_options, true, user_data);
+}
+
+static gboolean chr_handle_acquire_notify(Bluez5GattCharacteristic1 *object,
+		GDBusMethodInvocation *invocation,
+		GUnixFDList *fd_list, GVariant *arg_options,
+		gpointer user_data)
+{
+	return chr_handle_acquire(object, invocation, fd_list, arg_options, false, user_data);
+}
+
+static int export_chr(struct impl *impl)
+{
+	static const char * const flags[] = { "encrypt-read", "write-without-response",
+		"encrypt-write", "encrypt-notify", NULL };
+	GDBusObjectSkeleton *skeleton = NULL;
+	Bluez5GattCharacteristic1 *iface = NULL;
+	int res = -ENOMEM;
+	char path[128];
+
+	iface = bluez5_gatt_characteristic1_skeleton_new();
+	if (!iface)
+		goto done;
+
+	spa_scnprintf(path, sizeof(path), MIDI_CHR_PATH, impl->server_id);
+	skeleton = g_dbus_object_skeleton_new(path);
+	if (!skeleton)
+		goto done;
+	g_dbus_object_skeleton_add_interface(skeleton, G_DBUS_INTERFACE_SKELETON(iface));
+
+	bluez5_gatt_characteristic1_set_uuid(iface, BT_MIDI_CHR_UUID);
+	spa_scnprintf(path, sizeof(path), MIDI_SERVICE_PATH, impl->server_id);
+	bluez5_gatt_characteristic1_set_service(iface, path);
+	bluez5_gatt_characteristic1_set_write_acquired(iface, FALSE);
+	bluez5_gatt_characteristic1_set_notify_acquired(iface, FALSE);
+	bluez5_gatt_characteristic1_set_flags(iface, flags);
+
+	g_signal_connect(iface, "handle-read-value", G_CALLBACK(chr_handle_read_value), impl);
+	g_signal_connect(iface, "handle-acquire-write", G_CALLBACK(chr_handle_acquire_write), impl);
+	g_signal_connect(iface, "handle-acquire-notify", G_CALLBACK(chr_handle_acquire_notify), impl);
+
+	g_dbus_object_manager_server_export(impl->manager, skeleton);
+
+	impl->chr = g_object_ref(iface);
+
+	spa_log_debug(impl->log, "MIDI GATT Characteristic exported, path=%s",
+			g_dbus_object_get_object_path(G_DBUS_OBJECT(skeleton)));
+
+	res = 0;
+
+done:
+	g_clear_object(&iface);
+	g_clear_object(&skeleton);
+	return res;
+}
+
+
+/*
+ * MIDI service
+ */
+
+static int export_service(struct impl *impl)
+{
+	GDBusObjectSkeleton *skeleton = NULL;
+	Bluez5GattService1 *iface = NULL;
+	int res = -ENOMEM;
+	char path[128];
+
+	iface = bluez5_gatt_service1_skeleton_new();
+	if (!iface)
+		goto done;
+
+	spa_scnprintf(path, sizeof(path), MIDI_SERVICE_PATH, impl->server_id);
+	skeleton = g_dbus_object_skeleton_new(path);
+	if (!skeleton)
+		goto done;
+	g_dbus_object_skeleton_add_interface(skeleton, G_DBUS_INTERFACE_SKELETON(iface));
+
+	bluez5_gatt_service1_set_uuid(iface, BT_MIDI_SERVICE_UUID);
+	bluez5_gatt_service1_set_primary(iface, TRUE);
+
+	g_dbus_object_manager_server_export(impl->manager, skeleton);
+
+	spa_log_debug(impl->log, "MIDI GATT Service exported, path=%s",
+			g_dbus_object_get_object_path(G_DBUS_OBJECT(skeleton)));
+
+	res = 0;
+
+done:
+	g_clear_object(&iface);
+	g_clear_object(&skeleton);
+	return res;
+}
+
+
+/*
+ * Registration on all GattManagers
+ */
+
+static void manager_register_application_reply(GObject *source_object, GAsyncResult *res, gpointer user_data)
+{
+	MidiServerManagerProxy *manager = MIDI_SERVER_MANAGER_PROXY(source_object);
+	struct impl *impl = user_data;
+	GError *err = NULL;
+
+	bluez5_gatt_manager1_call_register_application_finish(
+		BLUEZ5_GATT_MANAGER1(source_object), res, &err);
+
+	if (g_error_matches(err, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
+		/* Operation canceled: user_data may be invalid by now */
+		g_error_free(err);
+		goto done;
+	}
+	if (err) {
+		spa_log_error(impl->log, "%s.RegisterApplication() failed: %s",
+				BLUEZ_GATT_MANAGER_INTERFACE,
+				err->message);
+		g_error_free(err);
+		goto done;
+	}
+
+	manager->registered = true;
+
+done:
+	g_clear_object(&manager->register_call);
+}
+
+static int manager_register_application(struct impl *impl, MidiServerManagerProxy *manager)
+{
+	GVariantBuilder builder;
+	GVariant *options;
+
+	if (manager->registered)
+		return 0;
+	if (manager->register_call)
+		return -EBUSY;
+
+	spa_log_debug(impl->log, "%s.RegisterApplication(%s) on %s",
+			BLUEZ_GATT_MANAGER_INTERFACE,
+			g_dbus_object_manager_get_object_path(G_DBUS_OBJECT_MANAGER(impl->manager)),
+			g_dbus_proxy_get_object_path(G_DBUS_PROXY(manager)));
+
+	manager->register_call = g_cancellable_new();
+	g_variant_builder_init(&builder, G_VARIANT_TYPE("a{sv}"));
+	options = g_variant_builder_end(&builder);
+	bluez5_gatt_manager1_call_register_application(BLUEZ5_GATT_MANAGER1(manager),
+			g_dbus_object_manager_get_object_path(G_DBUS_OBJECT_MANAGER(impl->manager)),
+			options,
+			manager->register_call,
+			manager_register_application_reply,
+			impl);
+
+	return 0;
+}
+
+static void midi_server_manager_proxy_init(MidiServerManagerProxy *manager)
+{
+}
+
+static void midi_server_manager_proxy_finalize(GObject *object)
+{
+	MidiServerManagerProxy *manager = MIDI_SERVER_MANAGER_PROXY(object);
+
+	g_cancellable_cancel(manager->register_call);
+	g_clear_object(&manager->register_call);
+}
+
+static void midi_server_manager_proxy_class_init(MidiServerManagerProxyClass *klass)
+{
+	GObjectClass *object_class = (GObjectClass *) klass;
+
+	object_class->finalize = midi_server_manager_proxy_finalize;
+}
+
+static void manager_update(struct dbus_monitor *monitor, GDBusInterface *iface)
+{
+	struct impl *impl = SPA_CONTAINER_OF(monitor, struct impl, monitor);
+
+	manager_register_application(impl, MIDI_SERVER_MANAGER_PROXY(iface));
+}
+
+static void manager_clear(struct dbus_monitor *monitor, GDBusInterface *iface)
+{
+	midi_server_manager_proxy_finalize(G_OBJECT(iface));
+}
+
+static void on_name_owner_change(struct dbus_monitor *monitor)
+{
+	struct impl *impl = SPA_CONTAINER_OF(monitor, struct impl, monitor);
+
+	/*
+	 * BlueZ disappeared/appeared. It does not appear to close the sockets
+	 * it quits, so we should force the chr release now.
+	 */
+	if (impl->cb->release)
+		impl->cb->release(impl->user_data);
+	chr_change_acquired(impl, true, false);
+	chr_change_acquired(impl, false, false);
+}
+
+static void monitor_start(struct impl *impl)
+{
+	struct dbus_monitor_proxy_type proxy_types[] = {
+		{ BLUEZ_GATT_MANAGER_INTERFACE, MIDI_SERVER_TYPE_MANAGER_PROXY, manager_update, manager_clear },
+		{ NULL, BLUEZ5_TYPE_OBJECT_PROXY, NULL, NULL },
+		{ NULL, G_TYPE_INVALID, NULL, NULL },
+	};
+
+	SPA_STATIC_ASSERT(SPA_N_ELEMENTS(proxy_types) <= DBUS_MONITOR_MAX_TYPES);
+
+	dbus_monitor_init(&impl->monitor, BLUEZ5_TYPE_OBJECT_MANAGER_CLIENT,
+			impl->log, impl->conn, BLUEZ_SERVICE, "/", proxy_types,
+			on_name_owner_change);
+}
+
+
+/*
+ * Object registration
+ */
+
+static int export_objects(struct impl *impl)
+{
+	int res = 0;
+	char path[128];
+
+	spa_scnprintf(path, sizeof(path), MIDI_SERVER_PATH, impl->server_id);
+	impl->manager = g_dbus_object_manager_server_new(path);
+	if (!impl->manager){
+		spa_log_error(impl->log, "Creating GDBus object manager failed");
+		goto fail;
+	}
+
+	if ((res = export_service(impl)) < 0)
+		goto fail;
+
+	if ((res = export_chr(impl)) < 0)
+		goto fail;
+
+	if ((res = export_dsc(impl)) < 0)
+		goto fail;
+
+	g_dbus_object_manager_server_set_connection(impl->manager, impl->conn);
+
+	return 0;
+
+fail:
+	res = (res < 0) ? res : ((errno > 0) ? -errno : -EIO);
+
+	spa_log_error(impl->log, "Failed to register BLE MIDI services in DBus: %s",
+			spa_strerror(res));
+
+	g_clear_object(&impl->manager);
+
+	return res;
+}
+
+struct spa_bt_midi_server *spa_bt_midi_server_new(const struct spa_bt_midi_server_cb *cb,
+		GDBusConnection *conn, struct spa_log *log, void *user_data)
+{
+	static unsigned int server_id = 0;
+	struct impl *impl;
+	char path[128];
+	int res = 0;
+
+	impl = calloc(1, sizeof(struct impl));
+	if (impl == NULL)
+		goto fail;
+
+	impl->server_id = server_id++;
+	impl->user_data = user_data;
+	impl->cb = cb;
+	impl->log = log;
+	impl->log_topic = SPA_LOG_TOPIC(0, "spa.bluez5.midi.server");
+	impl->conn = conn;
+	spa_log_topic_init(impl->log, &impl->log_topic);
+
+	if ((res = export_objects(impl)) < 0)
+		goto fail;
+
+	monitor_start(impl);
+
+	g_object_ref(impl->conn);
+
+	spa_scnprintf(path, sizeof(path), MIDI_CHR_PATH, impl->server_id);
+	impl->this.chr_path = strdup(path);
+
+	return &impl->this;
+
+fail:
+	res = (res < 0) ? res : ((errno > 0) ? -errno : -EIO);
+	free(impl);
+	errno = res;
+	return NULL;
+}
+
+void spa_bt_midi_server_destroy(struct spa_bt_midi_server *server)
+{
+	struct impl *impl = SPA_CONTAINER_OF(server, struct impl, this);
+
+	free((void *)impl->this.chr_path);
+	g_clear_object(&impl->chr);
+	dbus_monitor_clear(&impl->monitor);
+	g_clear_object(&impl->manager);
+	g_clear_object(&impl->conn);
+
+	free(impl);
+}
+
+void spa_bt_midi_server_released(struct spa_bt_midi_server *server, bool write)
+{
+	struct impl *impl = SPA_CONTAINER_OF(server, struct impl, this);
+
+	chr_change_acquired(impl, write, false);
+}