/*
 * Soft:        Keepalived is a failover program for the LVS project
 *              <www.linuxvirtualserver.org>. It monitor & manipulate
 *              a loadbalanced server pool using multi-layer checks.
 *
 * Part:        DBus server thread for VRRP
 *
 * Author:      Alexandre Cassen, <acassen@linux-vs.org>
 *
 *              This program is distributed in the hope that it will be useful,
 *              but WITHOUT ANY WARRANTY; without even the implied warranty of
 *              MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *              See the GNU General Public License for more details.
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License, or (at your option) any later version.
 *
 * Copyright (C) 2016-2017 Alexandre Cassen, <acassen@gmail.com>
 */

/* See https://git.gnome.org/browse/glib/tree/gio/tests/fdbus-example-server.c
 * and https://developer.gnome.org/gio/stable/GDBusConnection.html#gdbus-server
 * for examples of coding.
 *
 * Create a general /org/keepalived/Vrrp1/Vrrp DBus
 * object and a /org/keepalived/Vrrp1/Instance/#interface#/#group# object for
 * each VRRP instance.
 * Interface org.keepalived.Vrrp1.Vrrp implements methods PrintData,
 * PrintStats and signal VrrpStopped.
 * Interface com.keepalived.Vrrp1.Instance implements method SendGarp
 * (sends a single Gratuitous ARP from the given Instance),
 * signal VrrpStatusChange, and properties Name and State (retrievable
 * through calls to org.freedesktop.DBus.Properties.Get)
 *
 * Interface files need to be installed in /usr/share/dbus-1/interfaces/
 * A policy file, which determines who has access to the service, is
 * installed in /etc/dbus-1/system.d/. Sources for the policy and interface
 * files are in keepalived/dbus.
 *
 * To test the DBus service run a command like: dbus-send --system --dest=org.keepalived.Vrrp1 --print-reply object interface.method type:argument
 * e.g.
 * dbus-send --system --dest=org.keepalived.Vrrp1 --print-reply /org/keepalived/Vrrp1/Vrrp org.keepalived.Vrrp1.Vrrp.PrintData
 * or
 * dbus-send --system --dest=org.keepalived.Vrrp1 --print-reply /org/keepalived/Vrrp1/Instance/eth0/1/IPv4 org.freedesktop.DBus.Properties.Get string:'org.keepalived.Vrrp1.Instance' string:'State'
 *
 * To monitor signals, run:
 * dbus-monitor --system type='signal'
 *
 * d-feet is a useful program for interfacing with DBus
 */

#include "config.h"

#include <errno.h>
#include <pthread.h>
#include <semaphore.h>
#include <gio/gio.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/types.h>
#include <stdlib.h>
#include <stdint.h>

#include "vrrp_dbus.h"
#include "vrrp_data.h"
#include "vrrp_print.h"
#include "global_data.h"
#include "main.h"
#include "logger.h"
#include "utils.h"
#ifdef THREAD_DUMP
#include "scheduler.h"
#endif

typedef enum dbus_action {
	DBUS_ACTION_NONE,
	DBUS_PRINT_DATA,
	DBUS_PRINT_STATS,
	DBUS_PRINT_STATS_CLEAR,
	DBUS_RELOAD,
#ifdef _WITH_DBUS_CREATE_INSTANCE_
	DBUS_CREATE_INSTANCE,
	DBUS_DESTROY_INSTANCE,
#endif
	DBUS_SEND_GARP,
	DBUS_GET_NAME,
	DBUS_GET_STATUS,
} dbus_action_t;

typedef enum dbus_error {
	DBUS_SUCCESS,
	DBUS_INTERFACE_NOT_FOUND,
	DBUS_OBJECT_ALREADY_EXISTS,
	DBUS_INTERFACE_TOO_LONG,
	DBUS_INSTANCE_NOT_FOUND,
} dbus_error_t;

typedef struct dbus_queue_ent {
	dbus_action_t action;
	dbus_error_t reply;
	char *ifname;
	uint8_t vrid;
	uint8_t family;
	GVariant *args;
} dbus_queue_ent_t;

#define DBUS_SERVICE_NAME			"org.keepalived.Vrrp1"
#define DBUS_VRRP_INTERFACE			"org.keepalived.Vrrp1.Vrrp"
#define DBUS_VRRP_OBJECT_ROOT			"/org/keepalived/Vrrp1"
#define DBUS_VRRP_INSTANCE_PATH_DEFAULT_LENGTH	8
#define DBUS_VRRP_INSTANCE_INTERFACE		"org.keepalived.Vrrp1.Instance"
#define DBUS_VRRP_INTERFACE_FILE_PATH		"/usr/share/dbus-1/interfaces/org.keepalived.Vrrp1.Vrrp.xml"
#define DBUS_VRRP_INSTANCE_INTERFACE_FILE_PATH	"/usr/share/dbus-1/interfaces/org.keepalived.Vrrp1.Instance.xml"

static bool dbus_running;

/* Global file variables */
static const char * const no_interface = "none";
static GDBusNodeInfo *vrrp_introspection_data = NULL;
static GDBusNodeInfo *vrrp_instance_introspection_data = NULL;
static GDBusConnection *global_connection;
static GHashTable *objects;
static GMainLoop *loop;

/* Data passing between main vrrp thread and dbus thread */
dbus_queue_ent_t *ent_ptr;
static int dbus_in_pipe[2] = {-1, -1};
static int dbus_out_pipe[2] = {-1, -1};
static sem_t thread_end;

/* The only characters that are valid in a dbus path are A-Z, a-z, 0-9, _ */
static char *
set_valid_path(char *valid_path, const char *path)
{
	const char *str_in;
	char *str_out;

	for (str_in = path, str_out = valid_path; *str_in; str_in++, str_out++) {
		if (!isalnum(*str_in))
			*str_out = '_';
		else
			*str_out = *str_in;
	}
	*str_out = '\0';

	return valid_path;
}

static bool __attribute__ ((pure))
valid_path_cmp(const char *path, const char *valid_path)
{
	for ( ; *path && *valid_path; path++, valid_path++) {
		if (!isalnum(*path)) {
			if (*valid_path != '_')
				return true;
		}
		else if (*path != *valid_path)
			return true;
	}

	return *path != *valid_path;
}

static const char *
family_str(int family)
{
	if (family == AF_INET)
		return "IPv4";
	if (family == AF_INET6)
		return "IPv6";
	return "None";
}

static const char *
state_str(int state)
{
	switch (state) {
	case VRRP_STATE_INIT:
		return "Init";
	case VRRP_STATE_BACK:
		return "Backup";
	case VRRP_STATE_MAST:
		return "Master";
	case VRRP_STATE_FAULT:
		return "Fault";
	case VRRP_STATE_STOP:
		return "Stop";
	case VRRP_STATE_DELETED:
		return "Deleted";
	}
	return "Unknown";
}

static vrrp_t * __attribute__ ((pure))
get_vrrp_instance(const char *ifname, int vrid, int family)
{
	vrrp_t *vrrp;

	list_for_each_entry(vrrp, &vrrp_data->vrrp, e_list) {
		if (vrrp->ifp &&
		    vrrp->vrid == vrid &&
		    vrrp->family == family &&
		    !valid_path_cmp(VRRP_CONFIGURED_IFP(vrrp)->ifname, ifname))
			return vrrp;
	}

	return NULL;
}

static gboolean
unregister_object(const void * const key, gpointer value, __attribute__((unused)) gpointer user_data)
{
	if (g_hash_table_remove(objects, key))
		return g_dbus_connection_unregister_object(global_connection, GPOINTER_TO_UINT(value));
	return false;
}

static gboolean
remove_object(__attribute__((unused)) gpointer key, gpointer value, __attribute__((unused)) gpointer user_data)
{
	return g_dbus_connection_unregister_object(global_connection, GPOINTER_TO_UINT(value));
}

static gchar * __attribute__ ((malloc))
dbus_object_create_path_vrrp(void)
{
	return g_strconcat(DBUS_VRRP_OBJECT_ROOT,
			  global_data->network_namespace ? "/" : "", global_data->network_namespace ? global_data->network_namespace : "",
			  global_data->instance_name ? "/" : "", global_data->instance_name ? global_data->instance_name : "",

			  "/Vrrp", NULL);
}

static gchar * __attribute__ ((malloc))
dbus_object_create_path_instance(const gchar *interface, int vrid, sa_family_t family)
{
	gchar *object_path;
	char standardized_name[sizeof (PTR_CAST(vrrp_t, NULL))->ifp->ifname];
	gchar *vrid_str = g_strdup_printf("%d", vrid);

	set_valid_path(standardized_name, interface);

	object_path = g_strconcat(DBUS_VRRP_OBJECT_ROOT,
				  global_data->network_namespace ? "/" : "", global_data->network_namespace ? global_data->network_namespace : "",
				  global_data->instance_name ? "/" : "", global_data->instance_name ? global_data->instance_name : "",

				  "/Instance/",
				  standardized_name, "/", vrid_str,
				  "/", family_str(family),
				  NULL);

	g_free(vrid_str);
	return object_path;
}

static dbus_queue_ent_t *
process_method_call(dbus_queue_ent_t *ent)
{
	ssize_t ret;
	char buf = 0;

	if (!ent)
		return NULL;

	/* Tell the main thread that a queue entry is waiting. Any data works */
	ent_ptr = ent;
	if (write(dbus_in_pipe[1], &buf, 1) != 1)
		log_message(LOG_INFO, "Write from DBus thread to main thread failed");

	/* Wait for a response */
	while ((ret = read(dbus_out_pipe[0], &buf, 1)) == -1 && check_EINTR(errno))
		log_message(LOG_INFO, "dbus_out_pipe read returned EINTR");
	if (ret == -1)
		log_message(LOG_INFO, "DBus response read error - errno = %d", errno);

#ifdef DBUS_DEBUG
	if (ent->reply != DBUS_SUCCESS) {
		char *iname;

		if (ent->reply == DBUS_INTERFACE_NOT_FOUND)
			log_message(LOG_INFO, "Unable to find DBus requested instance %s/%d/%s", ent->ifname, ent->vrid, family_str(ent->family));
		else if (ent->reply == DBUS_OBJECT_ALREADY_EXISTS)
			log_message(LOG_INFO, "Unable to create DBus requested object with instance %s/%d/%s", ent->ifname, ent->vrid, family_str(ent->family));
		else if (ent->reply == DBUS_INSTANCE_NOT_FOUND) {
			g_variant_get(ent->args, "(s)", &iname);
			log_message(LOG_INFO, "Unable to find DBus requested instance %s", iname);
		}
		else
			log_message(LOG_INFO, "Unknown DBus reply %d", ent->reply);
	}
#endif

	return ent;
}

static void
get_interface_ids(const gchar *object_path, gchar *interface, uint8_t *vrid, uint8_t *family)
{
	int path_length = DBUS_VRRP_INSTANCE_PATH_DEFAULT_LENGTH;
	gchar **dirs;
	char *endptr;

	if(global_data->network_namespace)
		path_length++;
	if(global_data->instance_name)
		path_length++;

	/* object_path will have interface, vrid and family as
	 * the third to last, second to last and last levels */
	dirs = g_strsplit(object_path, "/", path_length);
	strcpy(interface, dirs[path_length-3]);
	*vrid = (uint8_t)strtoul(dirs[path_length-2], &endptr, 10);
	if (*endptr)
		log_message(LOG_INFO, "Dbus unexpected characters '%s' at end of number '%s'", endptr, dirs[path_length-2]);
	*family = !g_strcmp0(dirs[path_length-1], "IPv4") ? AF_INET : !g_strcmp0(dirs[path_length-1], "IPv6") ? AF_INET6 : AF_UNSPEC;

	/* We are finished with all the object_path strings now */
	g_strfreev(dirs);
}

/* handles reply to org.freedesktop.DBus.Properties.Get method on any object*/
static GVariant *
handle_get_property(__attribute__((unused)) GDBusConnection *connection,
		    __attribute__((unused)) const gchar     *sender,
					    const gchar     *object_path,
					    const gchar     *interface_name,
					    const gchar     *property_name,
					    GError	   **error,
		    __attribute__((unused)) gpointer	     user_data)
{
	GVariant *ret = NULL;
	dbus_queue_ent_t ent;
	char ifname_str[sizeof (PTR_CAST(vrrp_t, NULL))->ifp->ifname];
	int action;

	if (g_strcmp0(interface_name, DBUS_VRRP_INSTANCE_INTERFACE)) {
		log_message(LOG_INFO, "Interface %s has not been implemented yet", interface_name);
		return NULL;
	}

	if (!g_strcmp0(property_name, "Name"))
		action = DBUS_GET_NAME;
	else if (!g_strcmp0(property_name, "State"))
		action = DBUS_GET_STATUS;
	else {
		log_message(LOG_INFO, "Property %s does not exist", property_name);
		return NULL;
	}

	get_interface_ids(object_path, ifname_str, &ent.vrid, &ent.family);

	ent.action = action;
	ent.ifname = ifname_str;
	ent.args = NULL;
	process_method_call(&ent);
	if (ent.reply == DBUS_SUCCESS)
		ret = ent.args;
	else
		g_set_error(error, G_DBUS_ERROR, G_DBUS_ERROR_INVALID_ARGS, "Instance '%s/%d/%s' not found", ifname_str, ent.vrid, family_str(ent.family));

	return ret;
}

/* handles method_calls on any object */
static void
handle_method_call(__attribute__((unused)) GDBusConnection *connection,
		   __attribute__((unused)) const gchar	   *sender,
					   const gchar	   *object_path,
					   const gchar	   *interface_name,
					   const gchar	   *method_name,
#ifndef _WITH_DBUS_CREATE_INSTANCE_
		   __attribute__((unused))
#endif
					   GVariant *parameters,
		   GDBusMethodInvocation *invocation,
		   __attribute__((unused)) gpointer user_data)
{
#ifdef _WITH_DBUS_CREATE_INSTANCE_
	char *iname;
	char *ifname;
	size_t len;
	unsigned family;
#endif
	dbus_queue_ent_t ent;
	char ifname_str[sizeof (PTR_CAST(vrrp_t, NULL))->ifp->ifname];

	if (!g_strcmp0(interface_name, DBUS_VRRP_INTERFACE)) {
		if (!g_strcmp0(method_name, "PrintData")) {
			ent.action = DBUS_PRINT_DATA;
			process_method_call(&ent);
			g_dbus_method_invocation_return_value(invocation, NULL);
		}
		else if (g_strcmp0(method_name, "PrintStats") == 0) {
			ent.action = DBUS_PRINT_STATS;
			process_method_call(&ent);
			g_dbus_method_invocation_return_value(invocation, NULL);
		}
		else if (g_strcmp0(method_name, "PrintStatsClear") == 0) {
			ent.action = DBUS_PRINT_STATS_CLEAR;
			process_method_call(&ent);
			g_dbus_method_invocation_return_value(invocation, NULL);
		}
		else if (g_strcmp0(method_name, "ReloadConfig") == 0) {
			g_dbus_method_invocation_return_value(invocation, NULL);
			kill(getppid(), SIGHUP);
		}
#ifdef _WITH_DBUS_CREATE_INSTANCE_
		else if (g_strcmp0(method_name, "CreateInstance") == 0) {
			g_variant_get(parameters, "(ssuu)", &iname, &ifname, &ent.vrid, &family);
			len = strlen(ifname);
			if (len == 0 || len >= IFNAMSIZ) {
				log_message(LOG_INFO, "Interface name '%s' too long for CreateInstance", ifname);
				g_dbus_method_invocation_return_error(invocation, G_DBUS_ERROR, G_DBUS_ERROR_INVALID_ARGS, "Interface name empty or too long");
				return;
			}
			ent.action = DBUS_CREATE_INSTANCE;
			ent.ifname = ifname;
			ent.family = family == 4 ? AF_INET : family == 6 ? AF_INET6 : AF_UNSPEC;
			ent.args = g_variant_new("(s)", iname);
			process_method_call(&ent);
			g_variant_unref(ent.args);
			g_dbus_method_invocation_return_value(invocation, NULL);
		}
		else if (g_strcmp0(method_name, "DestroyInstance") == 0) {
// TODO - this should be on the instance
			ent.action = DBUS_DESTROY_INSTANCE;
			ent.args = parameters;
			process_method_call(&ent);

			if (ent.reply == DBUS_INSTANCE_NOT_FOUND) {
				g_variant_get(parameters, "(s)", &iname);
				g_dbus_method_invocation_return_error(invocation, G_DBUS_ERROR, G_DBUS_ERROR_INVALID_ARGS, "Instance '%s' not found", iname);
			}
			else
				g_dbus_method_invocation_return_value(invocation, NULL);
		}
#endif
		else {
			log_message(LOG_INFO, "Method %s has not been implemented yet", method_name);
			g_dbus_method_invocation_return_error(invocation, G_DBUS_ERROR, G_DBUS_ERROR_MATCH_RULE_NOT_FOUND, "Method not implemented");
		}

		return;
	}

	if (!g_strcmp0(interface_name, DBUS_VRRP_INSTANCE_INTERFACE)) {
		if (!g_strcmp0(method_name, "SendGarp")) {
			get_interface_ids(object_path, ifname_str, &ent.vrid, &ent.family);
			ent.action = DBUS_SEND_GARP;
			ent.ifname = ifname_str;
			process_method_call(&ent);
			if (ent.reply ==  DBUS_INTERFACE_NOT_FOUND)
				g_dbus_method_invocation_return_error(invocation, G_DBUS_ERROR, G_DBUS_ERROR_INVALID_ARGS, "Instance '%s/%d/%s' not found", ifname_str, ent.vrid, family_str(ent.family));
			else
				g_dbus_method_invocation_return_value(invocation, NULL);
		} else {
			log_message(LOG_INFO, "Method %s has not been implemented yet", method_name);
			g_dbus_method_invocation_return_error(invocation, G_DBUS_ERROR, G_DBUS_ERROR_MATCH_RULE_NOT_FOUND, "Method not implemented");
		}

		return;
	}

	log_message(LOG_INFO, "Interface %s has not been implemented yet", interface_name);
	g_dbus_method_invocation_return_error(invocation, G_DBUS_ERROR, G_DBUS_ERROR_MATCH_RULE_NOT_FOUND, "Interface not implemented");
}

static const GDBusInterfaceVTable interface_vtable =
{
	handle_method_call,
	handle_get_property,
	NULL, /* handle_set_property is null because we have no writeable property */
	{}
};

static int
dbus_create_object_params(const char *instance_name, const char *interface_name, int vrid, sa_family_t family, bool log_success)
{
	gchar *object_path;
	GError *local_error = NULL;

	if (g_hash_table_lookup(objects, instance_name)) {
		log_message(LOG_INFO, "An object for instance %s already exists", instance_name);
		return DBUS_OBJECT_ALREADY_EXISTS;
	}

	object_path = dbus_object_create_path_instance(interface_name, vrid, family);

	guint instance = g_dbus_connection_register_object(global_connection, object_path,
						vrrp_instance_introspection_data->interfaces[0],
						&interface_vtable, NULL, NULL, &local_error);
	if (local_error != NULL) {
		log_message(LOG_INFO, "Registering DBus object on %s failed: %s",
			    object_path, local_error->message);
		g_clear_error(&local_error);
	}

	if (instance) {
		g_hash_table_insert(objects, no_const_char_p(instance_name), GUINT_TO_POINTER(instance));
		if (log_success)
			log_message(LOG_INFO, "Added DBus object for instance %s on path %s", instance_name, object_path);
	}
	g_free(object_path);

	return DBUS_SUCCESS;
}

static void
dbus_create_object(vrrp_t *vrrp)
{
	dbus_create_object_params(vrrp->iname, vrrp->ifp ? IF_NAME(VRRP_CONFIGURED_IFP(vrrp)) : no_interface, vrrp->vrid, vrrp->family, false);
}

static bool
dbus_emit_signal(GDBusConnection *connection,
		 const gchar *object_path,
		 const gchar *interface_name,
		 const gchar *signal_name,
		 GVariant *parameters)
{
	GError *local_error = NULL;

	g_dbus_connection_emit_signal(connection, NULL, object_path, interface_name, signal_name, parameters,
				      &local_error);

	if (local_error != NULL) {
		log_message(LOG_INFO, "Emitting DBus signal %s.%s on %s failed: %s",
			    interface_name, signal_name, object_path, local_error->message);
		g_clear_error(&local_error);
		return false;
	}
	return true;
}

/* first function to be run when trying to own bus,
 * exports objects to the bus */
static void
on_bus_acquired(GDBusConnection *connection,
		const gchar     *name,
		__attribute__((unused)) gpointer user_data)
{
	global_connection = connection;
	gchar *path;
	vrrp_t *vrrp;
	GError *local_error = NULL;
	guint vrrp_guint;

	log_message(LOG_INFO, "Acquired DBus bus %s", name);

	/* register VRRP object */
	path = dbus_object_create_path_vrrp();
	vrrp_guint = g_dbus_connection_register_object(connection, path,
							 vrrp_introspection_data->interfaces[0],
							 &interface_vtable, NULL, NULL, &local_error);
	g_hash_table_insert(objects, no_const_char_p("__Vrrp__"), GUINT_TO_POINTER(vrrp_guint));
	if (local_error != NULL) {
		log_message(LOG_INFO, "Registering VRRP object on %s failed: %s",
			    path, local_error->message);
		g_clear_error(&local_error);
	}
	g_free(path);

	/* for each available VRRP instance, register an object */
	if (list_empty(&vrrp_data->vrrp))
		return;

	list_for_each_entry(vrrp, &vrrp_data->vrrp, e_list)
		dbus_create_object(vrrp);

	/* Send a signal to say we have started */
	path = dbus_object_create_path_vrrp();
	dbus_emit_signal(global_connection, path, DBUS_VRRP_INTERFACE, "VrrpStarted", NULL);
	g_free(path);

	/* Notify DBus of the state of our instances */
	list_for_each_entry(vrrp, &vrrp_data->vrrp, e_list)
		dbus_send_state_signal(vrrp);
}

/* run if bus name is acquired successfully */
static void
on_name_acquired(__attribute__((unused)) GDBusConnection *connection,
		 const gchar     *name,
		 __attribute__((unused)) gpointer user_data)
{
	log_message(LOG_INFO, "Acquired the name %s on the session bus", name);
}

/* run if bus name or connection are lost */
static void
on_name_lost(GDBusConnection *connection,
	     const gchar     *name,
	     __attribute__((unused)) gpointer user_data)
{
	log_message(LOG_INFO, "Lost the name %s on the session bus", name);
	global_connection = connection;
	g_hash_table_foreach_remove(objects, remove_object, NULL);
	objects = NULL;
	global_connection = NULL;
}

static const gchar*
read_file(const gchar* filepath)
{
	FILE * f;
	long length;
	gchar *ret = NULL;

	f = fopen(filepath, "r");
	if (f) {
		fseek(f, 0, SEEK_END);
		length = ftell(f);
		if (length < 0) {
			fclose(f);
			return NULL;
		}
		fseek(f, 0, SEEK_SET);

		/* We can't use MALLOC since it isn't thread safe */
		ret = MALLOC(length + 1);
		if (ret) {
			if (fread(ret, length, 1, f) != 1) {
				log_message(LOG_INFO, "Failed to read all of %s", filepath);
			}
			ret[length] = '\0';
		}
		else
			log_message(LOG_INFO, "Unable to read Dbus file %s", filepath);

		fclose(f);
	}
	return ret;
}

static void *
dbus_main(__attribute__ ((unused)) void *unused)
{
	const gchar *introspection_xml;
	guint owner_id;
	const char *service_name;

	objects = g_hash_table_new(g_str_hash, g_str_equal);

	/* DBus service org.keepalived.Vrrp1 exposes two interfaces, Vrrp and Instance.
	 * Vrrp is implemented by a single VRRP object for general purposes, such as printing
	 * data or signaling that the VRRP process has been stopped.
	 * Instance is implemented by an Instance object for every VRRP Instance in vrrp_data.
	 * It exposes instance specific methods and properties.
	 */
#ifdef DBUS_NEED_G_TYPE_INIT
	g_type_init();
#endif
	GError *error = NULL;

	/* read service interface data from xml files */
	introspection_xml = read_file(DBUS_VRRP_INTERFACE_FILE_PATH);
	if (!introspection_xml)
		return NULL;
	vrrp_introspection_data = g_dbus_node_info_new_for_xml(introspection_xml, &error);
	FREE_CONST(introspection_xml);
	if (error != NULL) {
		log_message(LOG_INFO, "Parsing DBus interface %s from file %s failed: %s",
			    DBUS_VRRP_INTERFACE, DBUS_VRRP_INTERFACE_FILE_PATH, error->message);
		g_clear_error(&error);
		return NULL;
	}

	introspection_xml = read_file(DBUS_VRRP_INSTANCE_INTERFACE_FILE_PATH);
	if (!introspection_xml)
		return NULL;
	vrrp_instance_introspection_data = g_dbus_node_info_new_for_xml(introspection_xml, &error);
	FREE_CONST(introspection_xml);
	if (error != NULL) {
		log_message(LOG_INFO, "Parsing DBus interface %s from file %s failed: %s",
			    DBUS_VRRP_INSTANCE_INTERFACE, DBUS_VRRP_INSTANCE_INTERFACE_FILE_PATH, error->message);
		g_clear_error(&error);
		return NULL;
	}

	service_name = global_data->dbus_service_name ? global_data->dbus_service_name : DBUS_SERVICE_NAME;
	owner_id = g_bus_own_name(G_BUS_TYPE_SYSTEM,
				  service_name,
				  G_BUS_NAME_OWNER_FLAGS_NONE,
				  on_bus_acquired,
				  on_name_acquired,
				  on_name_lost,
				  NULL,  /* user_data */
				  NULL); /* user_data_free_func */

	loop = g_main_loop_new(NULL, FALSE);
	g_main_loop_run(loop);

	/* cleanup after loop terminates */
	g_main_loop_unref(loop);
	g_bus_unown_name(owner_id);
	global_connection = NULL;

	sem_post(&thread_end);
	pthread_exit(0);
}

/* The following functions are run in the context of the main vrrp thread */

/* send signal VrrpStatusChange
 * containing the new state of vrrp */
void
dbus_send_state_signal(vrrp_t *vrrp)
{
	gchar *object_path;
	GVariant *args;

	/* the interface will go through the initial state changes before
	 * the main loop can be started and global_connection initialised */
	if (global_connection == NULL)
		return;

	object_path = dbus_object_create_path_instance(vrrp->ifp ? IF_NAME(VRRP_CONFIGURED_IFP(vrrp)) : no_interface, vrrp->vrid, vrrp->family);

	args = g_variant_new("(u)", vrrp->state);
	dbus_emit_signal(global_connection, object_path, DBUS_VRRP_INSTANCE_INTERFACE, "VrrpStatusChange", args);
	g_free(object_path);
}

/* send signal VrrpRestarted */
static void
dbus_send_reload_signal(void)
{
	gchar *path;

	if (global_connection == NULL)
		return;

	path = dbus_object_create_path_vrrp();
	dbus_emit_signal(global_connection, path, DBUS_VRRP_INTERFACE, "VrrpReloaded", NULL);
	g_free(path);
}

static gboolean
dbus_unregister_object(const char *str)
{
	gboolean ret = false;

	gpointer value = g_hash_table_lookup(objects, str);
	if (value) {
		ret = unregister_object(str, value, NULL);
		log_message(LOG_INFO, "Deleted DBus object for instance %s", str);
	}
#ifdef DBUS_DEBUG
	else
		log_message(LOG_INFO, "DBus object not found for instance %s", str);
#endif

	return ret;
}

void
dbus_remove_object(const vrrp_t *vrrp)
{
	dbus_unregister_object(vrrp->iname);
}

static void
handle_dbus_msg(__attribute__((unused)) thread_ref_t thread)
{
	dbus_queue_ent_t *ent;
	char recv_buf;
	vrrp_t *vrrp;
#ifdef _WITH_DBUS_CREATE_INSTANCE_
	gchar *name;
#endif

	if (read(dbus_in_pipe[0], &recv_buf, 1) != 1)
		log_message(LOG_INFO, "Read from DBus thread to vrrp thread failed");

	if ((ent = ent_ptr) != NULL) {
		ent->reply = DBUS_SUCCESS;

		if (ent->action == DBUS_PRINT_DATA) {
			log_message(LOG_INFO, "Printing VRRP data on DBus request");
			vrrp_print_data();

		}
		else if (ent->action == DBUS_PRINT_STATS) {
			log_message(LOG_INFO, "Printing VRRP stats on DBus request");
			vrrp_print_stats(false);
		}
		else if (ent->action == DBUS_PRINT_STATS_CLEAR) {
			log_message(LOG_INFO, "Printing and clearing VRRP stats on DBus request");
			vrrp_print_stats(true);
		}
#ifdef _WITH_DBUS_CREATE_INSTANCE_
		else if (ent->action == DBUS_CREATE_INSTANCE) {
			g_variant_get(ent->args, "(s)", &name);
			ent->reply = dbus_create_object_params(name, ent->ifname, ent->vrid, ent->family, true);
		}
		else if (ent->action == DBUS_DESTROY_INSTANCE) {
			g_variant_get(ent->args, "(s)", &name);
			if (!dbus_unregister_object(name))
				ent->reply = DBUS_INSTANCE_NOT_FOUND;
		}
#endif
		else if (ent->action == DBUS_SEND_GARP) {
			ent->reply = DBUS_INTERFACE_NOT_FOUND;
			vrrp = get_vrrp_instance(ent->ifname, ent->vrid, ent->family);
			if (vrrp) {
				log_message(LOG_INFO, "Sending garps on %s on DBus request", vrrp->iname);
				vrrp_send_link_update(vrrp, 1);
				ent->reply = DBUS_SUCCESS;
			}
		}
		else if (ent->action == DBUS_GET_NAME ||
			 ent->action == DBUS_GET_STATUS) {
			/* we look for the vrrp instance object that corresponds to our interface and group */
			ent->reply = DBUS_INTERFACE_NOT_FOUND;

			vrrp = get_vrrp_instance(ent->ifname, ent->vrid, ent->family);

			if (vrrp) {
				/* the property_name argument is the property we want to Get */
				if (ent->action == DBUS_GET_NAME)
					ent->args = g_variant_new("(s)", vrrp->iname);
				else if (ent->action == DBUS_GET_STATUS)
					ent->args = g_variant_new("(us)", vrrp->state, state_str(vrrp->state));
				else
					ent->args = NULL;	 /* How did we get here? */
				ent->reply = DBUS_SUCCESS;
			}
		}
		if (write(dbus_out_pipe[1], &recv_buf, 1) != 1)
			log_message(LOG_INFO, "Write from main thread to DBus thread failed");
	}

	thread_add_read(master, handle_dbus_msg, NULL, dbus_in_pipe[0], TIMER_NEVER, 0);
}

void
dbus_reload(const list_head_t *o, const list_head_t *n)
{
	vrrp_t *vrrp_n, *vrrp_o;

	if (!dbus_running)
		return;

	list_for_each_entry(vrrp_n, n, e_list) {
		const char *n_name;
		bool match_found;

		n_name = vrrp_n->ifp ? VRRP_CONFIGURED_IFP(vrrp_n)->ifname : no_interface;

		/* Try and find an instance with same vrid/family/interface that existed before and now */
		match_found = false;
		list_for_each_entry(vrrp_o, o, e_list) {
			if (vrrp_n->vrid == vrrp_o->vrid &&
			    vrrp_n->family == vrrp_o->family &&
// TODO - need to match on unicast_src if no interface
			    !strcmp(n_name, VRRP_CONFIGURED_IFP(vrrp_o)->ifname)) {
				/* If the old instance exists in the new config,
				 * then the dbus object will exist */
				if (!strcmp(vrrp_n->iname, vrrp_o->iname)) {
					match_found = true;
					g_hash_table_replace(objects, no_const_char_p(vrrp_n->iname), g_hash_table_lookup(objects, vrrp_o->iname));
					break;
				} else {
					gpointer instance;
					if ((instance = g_hash_table_lookup(objects, vrrp_o->iname))) {
						g_hash_table_remove(objects, vrrp_o->iname);
						g_hash_table_insert(objects, no_const_char_p(vrrp_n->iname), instance);
					}
					match_found = true;
					break;
				}

#if 0
				/* The following was in the original code, but I can't work out
				 * its purpose. Leaving it here for now in case it is really needed. */

				/* Check if the old instance name we found still exists
				 * (but has a different vrid/family/interface) */
				list_for_each_entry(vrrp_n3, n, e_list) {
					if (!strcmp(vrrp_o->iname, vrrp_n3->iname)) {
						match_found = true;
						break;
					}
				}
#endif
			}
		}

		if (match_found)
			continue;

		dbus_create_object(vrrp_n);
	}

	/* Signal we have reloaded */
	dbus_send_reload_signal();

	/* We need to reinstate the read thread */
	thread_add_read(master, handle_dbus_msg, NULL, dbus_in_pipe[0], TIMER_NEVER, 0);
}

bool
dbus_start(void)
{
	pthread_t dbus_thread;
	sigset_t sigset, cursigset;
	int flags;

	if (dbus_running)
		return false;

	if (open_pipe(dbus_in_pipe)) {
		log_message(LOG_INFO, "Unable to create inbound dbus pipe - disabling DBus");
		return false;
	}
	if (open_pipe(dbus_out_pipe)) {
		log_message(LOG_INFO, "Unable to create outbound dbus pipe - disabling DBus");
		close(dbus_in_pipe[0]);
		close(dbus_in_pipe[1]);
		dbus_in_pipe[0] = -1;
		dbus_out_pipe[0] = -1;
		return false;
	}

	/* We don't want the main thread to block when using the pipes,
	 * but the other side of the pipes should block. */
	flags = fcntl(dbus_in_pipe[1], F_GETFL);
	if (flags == -1 ||
	    fcntl(dbus_in_pipe[1], F_SETFL, flags & ~O_NONBLOCK) == -1)
		log_message(LOG_INFO, "Unable to set dbus thread in_pipe blocking - (%d - %m)", errno);
	flags = fcntl(dbus_out_pipe[0], F_GETFL);
	if (flags == -1 ||
	    fcntl(dbus_out_pipe[0], F_SETFL, flags & ~O_NONBLOCK) == -1)
		log_message(LOG_INFO, "Unable to set dbus thread out_pipe blocking - (%d - %m)", errno);

	thread_add_read(master, handle_dbus_msg, NULL, dbus_in_pipe[0], TIMER_NEVER, 0);

	/* Initialise the thread termination semaphore */
	sem_init(&thread_end, 0, 0);

	/* Block signals (all) we don't want the new thread to process */
	sigfillset(&sigset);
	pthread_sigmask(SIG_SETMASK, &sigset, &cursigset);

	/* Now create the dbus thread */
	pthread_create(&dbus_thread, NULL, &dbus_main, NULL);

	/* Reenable our signals */
	pthread_sigmask(SIG_SETMASK, &cursigset, NULL);

	dbus_running = true;

	return true;
}

void
dbus_stop(void)
{
	struct timespec thread_end_wait;
	int ret;
	gchar *path;

	if (!dbus_running)
		return;

	g_hash_table_foreach_remove(objects, remove_object, NULL);
	objects = NULL;

	if (global_connection != NULL) {
		path = dbus_object_create_path_vrrp();
		dbus_emit_signal(global_connection, path, DBUS_VRRP_INTERFACE, "VrrpStopped", NULL);
		g_free(path);
	}

	g_main_loop_quit(loop);

	g_dbus_node_info_unref(vrrp_introspection_data);
	g_dbus_node_info_unref(vrrp_instance_introspection_data);

	clock_gettime(CLOCK_REALTIME, &thread_end_wait);
	thread_end_wait.tv_sec += 1;
	while ((ret = sem_timedwait(&thread_end, &thread_end_wait)) == -1 && check_EINTR(errno));

	if (ret == -1 ) {
		if (errno == ETIMEDOUT)
			log_message(LOG_INFO, "DBus thread termination timed out");
		else
			log_message(LOG_INFO, "sem_timewait error %d", errno);
	}
	else {
		log_message(LOG_INFO, "Released DBus");
		sem_destroy(&thread_end);
	}

	dbus_running = false;

	close(dbus_in_pipe[0]);
	close(dbus_in_pipe[1]);
	dbus_in_pipe[0] = -1;
	dbus_in_pipe[0] = -1;
	close(dbus_out_pipe[0]);
	close(dbus_out_pipe[1]);
	dbus_out_pipe[0] = -1;
	dbus_out_pipe[0] = -1;
}

#ifdef THREAD_DUMP
void
register_vrrp_dbus_addresses(void)
{
	register_thread_address("handle_dbus_msg", handle_dbus_msg);
}
#endif
