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From:   Miao-chen Chou <mcchou@chromium.org>
To:     Bluetooth Kernel Mailing List <linux-bluetooth@vger.kernel.org>
Cc:     Alain Michaud <alainm@chromium.org>,
        Manish Mandlik <mmandlik@chromium.org>,
        Luiz Augusto von Dentz <luiz.von.dentz@intel.com>,
        Howard Chung <howardchung@google.com>,
        Miao-chen Chou <mcchou@chromium.org>,
        Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Subject: [BlueZ PATCH v1 3/7] adv_monitor: Implement RegisterMonitor()
Date:   Tue, 18 Aug 2020 15:26:39 -0700
Message-Id: <20200818152612.BlueZ.v1.3.I19ff9cdbd40fe453db0e81aec8bf94dd9490dce3@changeid>
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References: <20200818152612.BlueZ.v1.1.I205718871f4e636958904f3cfb171cfd381c54b1@changeid>
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This implements the RegisterMonitor() method handler of ADV monitor
manager interface.

The following tests were performed.
- Issue a RegisterMonitor() call with a valid path and expect a
success as return.
- Issue a RegisterMonitor() call with an invalid path and expect
org.bluez.Error.InvalidArguments as return.
- Issue two Registermonitor() calls with the same path and expect
org.bluez.Error.AlreadyExists.
- Verify the values of the registered paths with logging.
- Verify D-Bus disconnection callback was triggered when the client detach
from D-Bus.

Reviewed-by: Yun-Hao Chung <howardchung@google.com>
Reviewed-by: Manish Mandlik <mmandlik@chromium.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

 src/adv_monitor.c | 167 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 166 insertions(+), 1 deletion(-)

diff --git a/src/adv_monitor.c b/src/adv_monitor.c
index 4d02237e8..3d27ad18b 100644
--- a/src/adv_monitor.c
+++ b/src/adv_monitor.c
@@ -22,7 +22,9 @@
 #endif
 
 #define _GNU_SOURCE
+#include <errno.h>
 #include <stdint.h>
+#include <string.h>
 
 #include <glib.h>
 #include <dbus/dbus.h>
@@ -34,7 +36,9 @@
 #include "adapter.h"
 #include "dbus-common.h"
 #include "log.h"
+#include "src/error.h"
 #include "src/shared/mgmt.h"
+#include "src/shared/queue.h"
 #include "src/shared/util.h"
 
 #include "adv_monitor.h"
@@ -52,12 +56,170 @@ struct btd_adv_monitor_manager {
 	uint16_t max_num_monitors;
 	uint8_t max_num_patterns;
 
+	struct queue *apps;	/* apps who registered for Adv monitoring */
 };
 
+struct adv_monitor_app {
+	struct btd_adv_monitor_manager *manager;
+	char *owner;
+	char *path;
+
+	DBusMessage *reg;
+	GDBusClient *client;
+};
+
+struct app_match_data {
+	const char *owner;
+	const char *path;
+};
+
+/* Replies to an app's D-Bus message and unref it */
+static void app_reply_msg(struct adv_monitor_app *app, DBusMessage *reply)
+{
+	if (!app || !app->reg || !reply)
+		return;
+
+	g_dbus_send_message(btd_get_dbus_connection(), reply);
+	dbus_message_unref(app->reg);
+	app->reg = NULL;
+}
+
+/* Destroys an app object along with related D-Bus handlers */
+static void app_destroy(void *data)
+{
+	struct adv_monitor_app *app = data;
+
+	if (!app)
+		return;
+
+	DBG("Destroy Adv Monitor app %s at path %s", app->owner, app->path);
+
+	if (app->reg) {
+		app_reply_msg(app, btd_error_failed(app->reg,
+						"Adv Monitor app destroyed"));
+	}
+
+	if (app->client) {
+		g_dbus_client_set_disconnect_watch(app->client, NULL, NULL);
+		g_dbus_client_set_proxy_handlers(app->client, NULL, NULL, NULL,
+							NULL);
+		g_dbus_client_set_ready_watch(app->client, NULL, NULL);
+		g_dbus_client_unref(app->client);
+		app->client = NULL;
+	}
+
+	g_free(app->owner);
+	app->owner = NULL;
+	g_free(app->path);
+	app->path = NULL;
+
+	g_free(app);
+}
+
+/* Handles a D-Bus disconnection event of an app */
+static void app_disconnect_cb(DBusConnection *conn, void *user_data)
+{
+	struct adv_monitor_app *app = user_data;
+
+	btd_info(app->manager->adapter_id, "Adv Monitor app %s disconnected "
+			"from D-Bus", app->owner);
+	if (app && queue_remove(app->manager->apps, app))
+		app_destroy(app);
+}
+
+/* Creates an app object, initiates it and sets D-Bus event handlers */
+static struct adv_monitor_app *app_create(DBusConnection *conn,
+					const char *sender, const char *path,
+					struct btd_adv_monitor_manager *manager)
+{
+	struct adv_monitor_app *app;
+
+	if (!path || !sender || !manager)
+		return NULL;
+
+	app = g_new0(struct adv_monitor_app, 1);
+	if (!app)
+		return NULL;
+
+	app->owner = g_strdup(sender);
+	app->path = g_strdup(path);
+	app->manager = manager;
+	app->reg = NULL;
+
+	app->client = g_dbus_client_new(conn, sender, path);
+	if (!app->client) {
+		app_destroy(app);
+		return NULL;
+	}
+
+	g_dbus_client_set_disconnect_watch(app->client, app_disconnect_cb, app);
+	g_dbus_client_set_proxy_handlers(app->client, NULL, NULL, NULL, NULL);
+	g_dbus_client_set_ready_watch(app->client, NULL, NULL);
+
+	return app;
+}
+
+/* Matches an app based on its owner and path */
+static bool app_match(const void *a, const void *b)
+{
+	const struct adv_monitor_app *app = a;
+	const struct app_match_data *match = b;
+
+	if (match->owner && strcmp(app->owner, match->owner))
+		return false;
+
+	if (match->path && strcmp(app->path, match->path))
+		return false;
+
+	return true;
+}
+
+/* Handles a RegisterMonitor D-Bus call */
+static DBusMessage *register_monitor(DBusConnection *conn, DBusMessage *msg,
+					void *user_data)
+{
+	DBusMessageIter args;
+	struct app_match_data match;
+	struct adv_monitor_app *app;
+	struct btd_adv_monitor_manager *manager = user_data;
+
+	if (!dbus_message_iter_init(msg, &args))
+		return btd_error_invalid_args(msg);
+
+	if (dbus_message_iter_get_arg_type(&args) != DBUS_TYPE_OBJECT_PATH)
+		return btd_error_invalid_args(msg);
+
+	dbus_message_iter_get_basic(&args, &match.path);
+
+	if (!strlen(match.path) || !g_str_has_prefix(match.path, "/"))
+		return btd_error_invalid_args(msg);
+
+	match.owner = dbus_message_get_sender(msg);
+
+	if (queue_find(manager->apps, app_match, &match))
+		return btd_error_already_exists(msg);
+
+	app = app_create(conn, match.owner, match.path, manager);
+	if (!app) {
+		btd_error(manager->adapter_id,
+				"Failed to reserve %s for Adv Monitor app %s",
+				match.path, match.owner);
+		return btd_error_failed(msg,
+					"Failed to create Adv Monitor app");
+	}
+
+	queue_push_tail(manager->apps, app);
+
+	btd_info(manager->adapter_id, "Path %s reserved for Adv Monitor app %s",
+			match.path, match.owner);
+
+	return dbus_message_new_method_return(msg);
+}
+
 static const GDBusMethodTable adv_monitor_methods[] = {
 	{ GDBUS_METHOD("RegisterMonitor",
 					GDBUS_ARGS({ "application", "o" }),
-					NULL, NULL) },
+					NULL, register_monitor) },
 	{ GDBUS_ASYNC_METHOD("UnregisterMonitor",
 					GDBUS_ARGS({ "application", "o" }),
 					NULL, NULL) },
@@ -157,6 +319,7 @@ static struct btd_adv_monitor_manager *manager_new(
 	manager->mgmt = mgmt_ref(mgmt);
 	manager->adapter_id = btd_adapter_get_index(adapter);
 	manager->path = g_strdup(adapter_get_path(manager->adapter));
+	manager->apps = queue_new();
 
 	return manager;
 }
@@ -170,6 +333,8 @@ static void manager_free(struct btd_adv_monitor_manager *manager)
 	g_free(manager->path);
 	manager->path = NULL;
 
+	queue_destroy(manager->apps, app_destroy);
+
 	g_free(manager);
 }
 
-- 
2.26.2