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From:   Abhay Maheta <abhay.maheshbhai.maheta@intel.com>
To:     linux-bluetooth@vger.kernel.org
Cc:     Abhay Maheta <abhay.maheshbhai.maheta@intel.com>
Subject: [PATCH BlueZ v3 3/4] profiles: Add initial code for mcp plugin
Date:   Tue, 18 Oct 2022 10:08:30 +0530
Message-Id: <20221018043831.342821-4-abhay.maheshbhai.maheta@intel.com>
In-Reply-To: <20221018043831.342821-1-abhay.maheshbhai.maheta@intel.com>
References: <20221018043831.342821-1-abhay.maheshbhai.maheta@intel.com>
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This adds initial code for mcp plugin which handles Media Control Profile
and Generic Media Control Service for Client Role.
The plugin exposes dbus methods for media control operations
like play, pause which can be invoked using player menu
in bluetoothctl.
---
 Makefile.plugins     |   5 +
 configure.ac         |   4 +
 profiles/audio/mcp.c | 430 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 439 insertions(+)
 create mode 100644 profiles/audio/mcp.c

diff --git a/Makefile.plugins b/Makefile.plugins
index a3654980f..20cac384e 100644
--- a/Makefile.plugins
+++ b/Makefile.plugins
@@ -122,6 +122,11 @@ builtin_modules += bap
 builtin_sources += profiles/audio/bap.c
 endif
 
+if MCP
+builtin_modules += mcp
+builtin_sources += profiles/audio/mcp.c
+endif
+
 if VCP
 builtin_modules += vcp
 builtin_sources += profiles/audio/vcp.c
diff --git a/configure.ac b/configure.ac
index 79645e691..363a222a7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -199,6 +199,10 @@ AC_ARG_ENABLE(bap, AS_HELP_STRING([--disable-bap],
 		[disable BAP profile]), [enable_bap=${enableval}])
 AM_CONDITIONAL(BAP, test "${enable_bap}" != "no")
 
+AC_ARG_ENABLE(mcp, AS_HELP_STRING([--disable-mcp],
+        [disable MCP profile]), [enable_mcp=${enableval}])
+AM_CONDITIONAL(MCP, test "${enable_mcp}" != "no")
+
 AC_ARG_ENABLE(vcp, AS_HELP_STRING([--disable-vcp],
 		[disable VCP profile]), [enable_vcp=${enableval}])
 AM_CONDITIONAL(VCP, test "${enable_vcp}" != "no")
diff --git a/profiles/audio/mcp.c b/profiles/audio/mcp.c
new file mode 100644
index 000000000..f3ea330f9
--- /dev/null
+++ b/profiles/audio/mcp.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2020  Intel Corporation. All rights reserved.
+ *
+ *
+ */
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#define _GNU_SOURCE
+
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <glib.h>
+
+#include "gdbus/gdbus.h"
+
+#include "lib/bluetooth.h"
+#include "lib/hci.h"
+#include "lib/sdp.h"
+#include "lib/uuid.h"
+
+#include "src/dbus-common.h"
+#include "src/shared/util.h"
+#include "src/shared/att.h"
+#include "src/shared/queue.h"
+#include "src/shared/gatt-db.h"
+#include "src/shared/gatt-client.h"
+#include "src/shared/gatt-server.h"
+#include "src/shared/mcp.h"
+#include "src/shared/mcs.h"
+
+#include "btio/btio.h"
+#include "src/plugin.h"
+#include "src/adapter.h"
+#include "src/gatt-database.h"
+#include "src/device.h"
+#include "src/profile.h"
+#include "src/service.h"
+#include "src/log.h"
+#include "src/error.h"
+#include "player.h"
+
+#define GMCS_UUID_STR "00001849-0000-1000-8000-00805f9b34fb"
+
+struct mcp_data {
+	struct btd_device *device;
+	struct btd_service *service;
+	struct bt_mcp *mcp;
+	unsigned int state_id;
+
+	struct media_player *mp;
+};
+
+static void mcp_debug(const char *str, void *user_data)
+{
+	DBG_IDX(0xffff, "%s", str);
+}
+
+static char *name2utf8(const uint8_t *name, uint16_t len)
+{
+	char utf8_name[HCI_MAX_NAME_LENGTH + 2];
+	int i;
+
+	if (g_utf8_validate((const char *) name, len, NULL))
+		return g_strndup((char *) name, len);
+
+	len = MIN(len, sizeof(utf8_name) - 1);
+
+	memset(utf8_name, 0, sizeof(utf8_name));
+	strncpy(utf8_name, (char *) name, len);
+
+	/* Assume ASCII, and replace all non-ASCII with spaces */
+	for (i = 0; utf8_name[i] != '\0'; i++) {
+		if (!isascii(utf8_name[i]))
+			utf8_name[i] = ' ';
+	}
+
+	/* Remove leading and trailing whitespace characters */
+	g_strstrip(utf8_name);
+
+	return g_strdup(utf8_name);
+}
+
+static const char *mcp_status_val_to_string(uint8_t status)
+{
+	switch (status) {
+	case BT_MCS_STATUS_PLAYING:
+		return "playing";
+	case BT_MCS_STATUS_PAUSED:
+		return "paused";
+	case BT_MCS_STATUS_INACTIVE:
+		return "stopped";
+	case BT_MCS_STATUS_SEEKING:
+		/* TODO: find a way for fwd/rvs seeking, probably by storing
+		 * control point operation sent before
+		 */
+		return "forward-seek";
+	default:
+		return "error";
+	}
+}
+
+static struct mcp_data *mcp_data_new(struct btd_device *device)
+{
+	struct mcp_data *data;
+
+	data = new0(struct mcp_data, 1);
+	data->device = device;
+
+	return data;
+}
+
+static void cb_player_name(struct bt_mcp *mcp,  const uint8_t *value,
+					uint16_t length)
+{
+	char *name;
+	struct media_player *mp = bt_mcp_get_user_data(mcp);
+
+	name = name2utf8(value, length);
+	DBG("Media Player Name %s", (const char *)name);
+
+	media_player_set_name(mp, name);
+
+	g_free(name);
+}
+
+static void cb_track_changed(struct bt_mcp *mcp)
+{
+	DBG("Track Changed");
+	/* Since track changed has happened
+	 * track title notification is expected
+	 */
+}
+
+static void cb_track_title(struct bt_mcp *mcp, const uint8_t *value,
+					uint16_t length)
+{
+	char *name;
+	uint16_t len;
+	struct media_player *mp = bt_mcp_get_user_data(mcp);
+
+	name = name2utf8(value, length);
+	len = strlen(name);
+
+	DBG("Track Title %s", (const char *)name);
+
+	media_player_set_metadata(mp, NULL, "Title", name, len);
+	media_player_metadata_changed(mp);
+
+	g_free(name);
+}
+
+static void cb_track_duration(struct bt_mcp *mcp, int32_t duration)
+{
+	struct media_player *mp = bt_mcp_get_user_data(mcp);
+	unsigned char buf[10];
+
+	/* MCP defines duration is int32 but api takes it as uint32 */
+	sprintf((char *)buf, "%d", duration);
+	media_player_set_metadata(mp, NULL, "Duration", buf, sizeof(buf));
+	media_player_metadata_changed(mp);
+}
+
+static void cb_track_position(struct bt_mcp *mcp, int32_t duration)
+{
+	struct media_player *mp = bt_mcp_get_user_data(mcp);
+
+	/* MCP defines duration is int32 but api takes it as uint32 */
+	media_player_set_position(mp, duration);
+}
+
+static void cb_media_state(struct bt_mcp *mcp, uint8_t status)
+{
+	struct media_player *mp = bt_mcp_get_user_data(mcp);
+
+	media_player_set_status(mp, mcp_status_val_to_string(status));
+}
+
+static const struct bt_mcp_event_callback cbs = {
+	.player_name			= &cb_player_name,
+	.track_changed			= &cb_track_changed,
+	.track_title			= &cb_track_title,
+	.track_duration			= &cb_track_duration,
+	.track_position			= &cb_track_position,
+	.playback_speed			= NULL,
+	.seeking_speed			= NULL,
+	.play_order				= NULL,
+	.play_order_supported	= NULL,
+	.media_state			= &cb_media_state,
+	.content_control_id		= NULL,
+};
+
+static int ct_play(struct media_player *mp, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	return bt_mcp_play(mcp);
+}
+
+static int ct_pause(struct media_player *mp, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	return bt_mcp_pause(mcp);
+}
+
+static int ct_stop(struct media_player *mp, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	return bt_mcp_stop(mcp);
+}
+
+static const struct media_player_callback ct_cbs = {
+	.set_setting	= NULL,
+	.play		= &ct_play,
+	.pause		= &ct_pause,
+	.stop		= &ct_stop,
+	.next		= NULL,
+	.previous	= NULL,
+	.fast_forward	= NULL,
+	.rewind		= NULL,
+	.press		= NULL,
+	.hold		= NULL,
+	.release	= NULL,
+	.list_items	= NULL,
+	.change_folder	= NULL,
+	.search		= NULL,
+	.play_item	= NULL,
+	.add_to_nowplaying = NULL,
+	.total_items = NULL,
+};
+
+static int mcp_probe(struct btd_service *service)
+{
+	struct btd_device *device = btd_service_get_device(service);
+	struct btd_adapter *adapter = device_get_adapter(device);
+	struct btd_gatt_database *database = btd_adapter_get_database(adapter);
+	struct mcp_data *data = btd_service_get_user_data(service);
+	char addr[18];
+
+	ba2str(device_get_address(device), addr);
+	DBG("%s", addr);
+
+	/* Ignore, if we were probed for this device already */
+	if (data) {
+		error("Profile probed twice for the same device!");
+		return -EINVAL;
+	}
+
+	data = mcp_data_new(device);
+	data->service = service;
+
+	data->mcp = bt_mcp_new(btd_gatt_database_get_db(database),
+					btd_device_get_gatt_db(device));
+
+	bt_mcp_set_debug(data->mcp, mcp_debug, NULL, NULL);
+	btd_service_set_user_data(service, data);
+
+	return 0;
+}
+
+static void mcp_data_free(struct mcp_data *data)
+{
+	DBG("");
+
+	if (data->service) {
+		btd_service_set_user_data(data->service, NULL);
+		bt_mcp_set_user_data(data->mcp, NULL);
+	}
+
+	if (data->mp) {
+		media_player_destroy(data->mp);
+		data->mp = NULL;
+	}
+
+	bt_mcp_unref(data->mcp);
+	free(data);
+}
+
+static void mcp_data_remove(struct mcp_data *data)
+{
+	DBG("data %p", data);
+
+	mcp_data_free(data);
+}
+
+static void mcp_remove(struct btd_service *service)
+{
+	struct btd_device *device = btd_service_get_device(service);
+	struct mcp_data *data;
+	char addr[18];
+
+	ba2str(device_get_address(device), addr);
+	DBG("%s", addr);
+
+	data = btd_service_get_user_data(service);
+	if (!data) {
+		error("MCP service not handled by profile");
+		return;
+	}
+
+	mcp_data_remove(data);
+}
+
+static int mcp_accept(struct btd_service *service)
+{
+	struct btd_device *device = btd_service_get_device(service);
+	struct bt_gatt_client *client = btd_device_get_gatt_client(device);
+	struct mcp_data *data = btd_service_get_user_data(service);
+	char addr[18];
+
+	ba2str(device_get_address(device), addr);
+	DBG("%s", addr);
+
+	bt_mcp_attach(data->mcp, client);
+
+	data->mp = media_player_controller_create(device_get_path(device), 0);
+	if (data->mp == NULL) {
+		DBG("Unable to create Media Player");
+		return -EINVAL;
+	}
+
+	media_player_set_callbacks(data->mp, &ct_cbs, data->mcp);
+
+	bt_mcp_set_user_data(data->mcp, data->mp);
+	bt_mcp_set_event_callbacks(data->mcp, &cbs, data->mp);
+	btd_service_connecting_complete(service, 0);
+
+	return 0;
+}
+
+static int mcp_connect(struct btd_service *service)
+{
+	struct btd_device *device = btd_service_get_device(service);
+	char addr[18];
+
+	ba2str(device_get_address(device), addr);
+	DBG("%s", addr);
+
+	return 0;
+}
+
+static int mcp_disconnect(struct btd_service *service)
+{
+	struct btd_device *device = btd_service_get_device(service);
+	struct mcp_data *data = btd_service_get_user_data(service);
+	char addr[18];
+
+	ba2str(device_get_address(device), addr);
+	DBG("%s", addr);
+
+	if (data->mp) {
+		media_player_destroy(data->mp);
+		data->mp = NULL;
+	}
+
+	bt_mcp_detach(data->mcp);
+
+	btd_service_disconnecting_complete(service, 0);
+
+	return 0;
+}
+
+static int media_control_server_probe(struct btd_profile *p,
+						struct btd_adapter *adapter)
+{
+	struct btd_gatt_database *database = btd_adapter_get_database(adapter);
+
+	bt_mcp_register(btd_gatt_database_get_db(database));
+
+	return 0;
+}
+
+static void media_control_server_remove(struct btd_profile *p,
+						struct btd_adapter *adapter)
+{
+
+}
+
+static struct btd_profile mcp_profile = {
+	.name			= "mcp",
+	.priority		= BTD_PROFILE_PRIORITY_MEDIUM,
+	.remote_uuid	= GMCS_UUID_STR,
+	.device_probe	= mcp_probe,
+	.device_remove	= mcp_remove,
+	.accept			= mcp_accept,
+	.connect		= mcp_connect,
+	.disconnect		= mcp_disconnect,
+
+	.adapter_probe	= media_control_server_probe,
+	.adapter_remove = media_control_server_remove,
+};
+
+static int mcp_init(void)
+{
+	DBG("");
+
+	if (!(g_dbus_get_flags() & G_DBUS_FLAG_ENABLE_EXPERIMENTAL)) {
+		warn("D-Bus experimental not enabled");
+		return -ENOTSUP;
+	}
+
+	btd_profile_register(&mcp_profile);
+	return 0;
+}
+
+static void mcp_exit(void)
+{
+	DBG("");
+
+	if (g_dbus_get_flags() & G_DBUS_FLAG_ENABLE_EXPERIMENTAL)
+		btd_profile_unregister(&mcp_profile);
+}
+
+BLUETOOTH_PLUGIN_DEFINE(mcp, VERSION, BLUETOOTH_PLUGIN_PRIORITY_DEFAULT,
+							mcp_init, mcp_exit)
-- 
2.25.1