profiles: Add initial code for vcp plugin

This adds initial code for vcp plugin which handles Volume Control
Profile and Volume Control Service.

Makefile.plugins

@@ -121,3 +121,8 @@ if BAP
 builtin_modules += bap
 builtin_sources += profiles/audio/bap.c
 endif
+
+if VCP
+builtin_modules += vcp
+builtin_sources += profiles/audio/vcp.c
+endif

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(vcp, AS_HELP_STRING([--disable-vcp],
+		[disable VCP profile]), [enable_vcp=${enableval}])
+AM_CONDITIONAL(VCP, test "${enable_vcp}" != "no")
+
 AC_ARG_ENABLE(tools, AS_HELP_STRING([--disable-tools],
 		[disable Bluetooth tools]), [enable_tools=${enableval}])
 AM_CONDITIONAL(TOOLS, test "${enable_tools}" != "no")

profiles/audio/vcp.c

@@ -0,0 +1,311 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2022  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 <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/vcp.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"
+
+#define VCS_UUID_STR "00001844-0000-1000-8000-00805f9b34fb"
+#define MEDIA_ENDPOINT_INTERFACE "org.bluez.MediaEndpoint1"
+
+struct vcp_data {
+	struct btd_device *device;
+	struct btd_service *service;
+	struct bt_vcp *vcp;
+};
+
+static struct queue *sessions;
+
+static int vcp_disconnect(struct btd_service *service)
+{
+	DBG("");
+	return 0;
+}
+
+static struct vcp_data *vcp_data_new(struct btd_device *device)
+{
+	struct vcp_data *data;
+
+	data = new0(struct vcp_data, 1);
+	data->device = device;
+
+	return data;
+}
+
+static void vcp_data_add(struct vcp_data *data)
+{
+	DBG("data %p", data);
+
+	if (queue_find(sessions, NULL, data)) {
+		error("data %p already added", data);
+		return;
+	}
+
+	if (!sessions)
+		sessions = queue_new();
+
+	queue_push_tail(sessions, data);
+
+	if (data->service)
+		btd_service_set_user_data(data->service, data);
+}
+
+static bool match_data(const void *data, const void *match_data)
+{
+	const struct vcp_data *vdata = data;
+	const struct bt_vcp *vcp = match_data;
+
+	return vdata->vcp == vcp;
+}
+
+static void vcp_data_free(struct vcp_data *data)
+{
+	if (data->service) {
+		btd_service_set_user_data(data->service, NULL);
+		bt_vcp_set_user_data(data->vcp, NULL);
+	}
+
+	bt_vcp_unref(data->vcp);
+	free(data);
+}
+
+static void vcp_data_remove(struct vcp_data *data)
+{
+	DBG("data %p", data);
+
+	if (!queue_remove(sessions, data))
+		return;
+
+	vcp_data_free(data);
+
+	if (queue_isempty(sessions)) {
+		queue_destroy(sessions, NULL);
+		sessions = NULL;
+	}
+}
+
+static void vcp_detached(struct bt_vcp *vcp, void *user_data)
+{
+	struct vcp_data *data;
+
+	DBG("%p", vcp);
+
+	data = queue_find(sessions, match_data, vcp);
+	if (!data) {
+		error("Unable to find vcp session");
+		return;
+	}
+
+	vcp_data_remove(data);
+}
+
+static void vcp_attached(struct bt_vcp *vcp, void *user_data)
+{
+	struct vcp_data *data;
+	struct bt_att *att;
+	struct btd_device *device;
+
+	DBG("%p", vcp);
+
+	data = queue_find(sessions, match_data, vcp);
+	if (data)
+		return;
+
+	att = bt_vcp_get_att(vcp);
+	if (!att)
+		return;
+
+	device = btd_adapter_find_device_by_fd(bt_att_get_fd(att));
+	if (!device) {
+		error("Unable to find device");
+		return;
+	}
+
+	data = vcp_data_new(device);
+	data->vcp = vcp;
+
+	vcp_data_add(data);
+}
+
+static int vcp_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 vcp_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 = vcp_data_new(device);
+	data->service = service;
+
+	data->vcp = bt_vcp_new(btd_gatt_database_get_db(database),
+					btd_device_get_gatt_db(device));
+	if (!data->vcp) {
+		error("Unable to create VCP instance");
+		free(data);
+		return -EINVAL;
+	}
+
+	vcp_data_add(data);
+
+	bt_vcp_set_user_data(data->vcp, service);
+
+	return 0;
+}
+
+static void vcp_remove(struct btd_service *service)
+{
+	struct btd_device *device = btd_service_get_device(service);
+	struct vcp_data *data;
+	char addr[18];
+
+	ba2str(device_get_address(device), addr);
+	DBG("%s", addr);
+
+	data = btd_service_get_user_data(service);
+	if (!data) {
+		error("VCP service not handled by profile");
+		return;
+	}
+
+	vcp_data_remove(data);
+}
+
+static int vcp_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 vcp_data *data = btd_service_get_user_data(service);
+	char addr[18];
+
+	ba2str(device_get_address(device), addr);
+	DBG("%s", addr);
+
+	if (!data) {
+		error("VCP service not handled by profile");
+		return -EINVAL;
+	}
+
+	if (!bt_vcp_attach(data->vcp, client)) {
+		error("VCP unable to attach");
+		return -EINVAL;
+	}
+
+	btd_service_connecting_complete(service, 0);
+
+	return 0;
+}
+
+static int vcp_server_probe(struct btd_profile *p,
+				  struct btd_adapter *adapter)
+{
+	struct btd_gatt_database *database = btd_adapter_get_database(adapter);
+
+	DBG("VCP path %s", adapter_get_path(adapter));
+
+	bt_vcp_add_db(btd_gatt_database_get_db(database));
+
+	return 0;
+}
+
+static void vcp_server_remove(struct btd_profile *p,
+					struct btd_adapter *adapter)
+{
+	DBG("VCP remove Adapter");
+}
+
+static struct btd_profile vcp_profile = {
+	.name		= "vcp",
+	.priority	= BTD_PROFILE_PRIORITY_MEDIUM,
+	.remote_uuid	= VCS_UUID_STR,
+
+	.device_probe	= vcp_probe,
+	.device_remove	= vcp_remove,
+
+	.accept		= vcp_accept,
+	.disconnect	= vcp_disconnect,
+
+	.adapter_probe = vcp_server_probe,
+	.adapter_remove = vcp_server_remove,
+};
+
+static unsigned int vcp_id = 0;
+
+static int vcp_init(void)
+{
+	if (!(g_dbus_get_flags() & G_DBUS_FLAG_ENABLE_EXPERIMENTAL)) {
+		warn("D-Bus experimental not enabled");
+		return -ENOTSUP;
+	}
+
+	btd_profile_register(&vcp_profile);
+	vcp_id = bt_vcp_register(vcp_attached, vcp_detached, NULL);
+
+	return 0;
+}
+
+static void vcp_exit(void)
+{
+	if (g_dbus_get_flags() & G_DBUS_FLAG_ENABLE_EXPERIMENTAL) {
+		btd_profile_unregister(&vcp_profile);
+		bt_vcp_unregister(vcp_id);
+	}
+}
+
+BLUETOOTH_PLUGIN_DEFINE(vcp, VERSION, BLUETOOTH_PLUGIN_PRIORITY_DEFAULT,
+							vcp_init, vcp_exit)