// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2011 - 2015 Red Hat, Inc.
 */

#include "nm-default.h"

#include "nm-firewall-manager.h"

#include "nm-glib-aux/nm-dbus-aux.h"
#include "c-list/src/c-list.h"

#include "NetworkManagerUtils.h"
#include "nm-dbus-manager.h"

#define FIREWALL_DBUS_SERVICE         "org.fedoraproject.FirewallD1"
#define FIREWALL_DBUS_PATH            "/org/fedoraproject/FirewallD1"
#define FIREWALL_DBUS_INTERFACE_ZONE  "org.fedoraproject.FirewallD1.zone"

/*****************************************************************************/

enum {
	STATE_CHANGED,
	LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = { 0 };

typedef struct {
	GDBusConnection *dbus_connection;

	GCancellable *get_name_owner_cancellable;

	CList pending_calls;

	guint name_owner_changed_id;

	bool dbus_inited:1;
	bool running:1;
} NMFirewallManagerPrivate;

struct _NMFirewallManager {
	GObject parent;
	NMFirewallManagerPrivate _priv;
};

struct _NMFirewallManagerClass {
	GObjectClass parent;
};

G_DEFINE_TYPE (NMFirewallManager, nm_firewall_manager, G_TYPE_OBJECT)

#define NM_FIREWALL_MANAGER_GET_PRIVATE(self) _NM_GET_PRIVATE (self, NMFirewallManager, NM_IS_FIREWALL_MANAGER)

/*****************************************************************************/

NM_DEFINE_SINGLETON_GETTER (NMFirewallManager, nm_firewall_manager_get, NM_TYPE_FIREWALL_MANAGER);

/*****************************************************************************/

typedef enum {
	OPS_TYPE_ADD = 1,
	OPS_TYPE_CHANGE,
	OPS_TYPE_REMOVE,
} OpsType;

struct _NMFirewallManagerCallId {
	CList lst;

	NMFirewallManager *self;

	char *iface;

	NMFirewallManagerAddRemoveCallback callback;
	gpointer user_data;

	union {
		struct {
			GCancellable *cancellable;
			GVariant *arg;
		} dbus;
		struct {
			guint id;
		} idle;
	};

	OpsType ops_type;

	bool is_idle:1;
};

/*****************************************************************************/

static const char *
_ops_type_to_string (OpsType ops_type)
{
	switch (ops_type) {
	case OPS_TYPE_ADD:    return "add";
	case OPS_TYPE_REMOVE: return "remove";
	case OPS_TYPE_CHANGE: return "change";
	}
	nm_assert_not_reached ();
	return NULL;
}

#define _NMLOG_DOMAIN      LOGD_FIREWALL
#define _NMLOG_PREFIX_NAME "firewall"
#define _NMLOG(level, call_id, ...) \
    G_STMT_START { \
        if (nm_logging_enabled ((level), (_NMLOG_DOMAIN))) { \
            NMFirewallManagerCallId *_call_id = (call_id); \
            char _prefix_name[30]; \
            char _prefix_info[100]; \
            \
            _nm_log ((level), (_NMLOG_DOMAIN), 0, NULL, NULL, \
                     "%s: %s" _NM_UTILS_MACRO_FIRST(__VA_ARGS__), \
                     (self) != singleton_instance \
                        ? ({ \
                                g_snprintf (_prefix_name, \
                                            sizeof (_prefix_name), \
                                            "%s["NM_HASH_OBFUSCATE_PTR_FMT"]", \
                                            ""_NMLOG_PREFIX_NAME,\
                                            NM_HASH_OBFUSCATE_PTR (self)); \
                                _prefix_name; \
                           }) \
                        : _NMLOG_PREFIX_NAME, \
                     _call_id \
                        ? ({ \
                                g_snprintf (_prefix_info, \
                                            sizeof (_prefix_info), \
                                            "["NM_HASH_OBFUSCATE_PTR_FMT",%s%s:%s%s%s]: ", \
                                            NM_HASH_OBFUSCATE_PTR (_call_id), \
                                            _ops_type_to_string (_call_id->ops_type), \
                                            _call_id->is_idle ? "*" : "", \
                                            NM_PRINT_FMT_QUOTE_STRING (_call_id->iface)); \
                                _prefix_info; \
                           }) \
                        : "" \
                     _NM_UTILS_MACRO_REST(__VA_ARGS__)); \
        } \
    } G_STMT_END

/*****************************************************************************/

static gboolean
_get_running (NMFirewallManagerPrivate *priv)
{
	/* when starting, we need to asynchronously check whether there is
	 * a name owner. During that time we optimistially assume that the
	 * service is indeed running. That is the time when we queue the
	 * requests, and they will be started once the get-name-owner call
	 * returns. */
	return    priv->running
	       || (   priv->dbus_connection
	           && !priv->dbus_inited);
}

gboolean
nm_firewall_manager_get_running (NMFirewallManager *self)
{
	g_return_val_if_fail (NM_IS_FIREWALL_MANAGER (self), FALSE);

	return _get_running (NM_FIREWALL_MANAGER_GET_PRIVATE (self));
}

/*****************************************************************************/

static NMFirewallManagerCallId *
_cb_info_create (NMFirewallManager *self,
                 OpsType ops_type,
                 const char *iface,
                 const char *zone,
                 NMFirewallManagerAddRemoveCallback callback,
                 gpointer user_data)
{
	NMFirewallManagerPrivate *priv = NM_FIREWALL_MANAGER_GET_PRIVATE (self);
	NMFirewallManagerCallId *call_id;

	call_id = g_slice_new0 (NMFirewallManagerCallId);

	call_id->self = g_object_ref (self);
	call_id->ops_type = ops_type;
	call_id->iface = g_strdup (iface);
	call_id->callback = callback;
	call_id->user_data = user_data;

	if (_get_running (priv)) {
		call_id->is_idle = FALSE;
		call_id->dbus.arg = g_variant_new ("(ss)", zone ?: "", iface);
	} else
		call_id->is_idle = TRUE;

	c_list_link_tail (&priv->pending_calls, &call_id->lst);

	return call_id;
}

static void
_cb_info_complete (NMFirewallManagerCallId *call_id,
                   GError *error)
{
	c_list_unlink (&call_id->lst);

	if (call_id->callback)
		call_id->callback (call_id->self, call_id, error, call_id->user_data);

	if (call_id->is_idle)
		nm_clear_g_source (&call_id->idle.id);
	else {
		nm_g_variant_unref (call_id->dbus.arg);
		nm_clear_g_cancellable (&call_id->dbus.cancellable);
	}
	g_free (call_id->iface);
	g_object_unref (call_id->self);
	nm_g_slice_free (call_id);
}

static gboolean
_handle_idle_cb (gpointer user_data)
{
	NMFirewallManager *self;
	NMFirewallManagerCallId *call_id = user_data;

	nm_assert (call_id);
	nm_assert (NM_IS_FIREWALL_MANAGER (call_id->self));
	nm_assert (call_id->is_idle);
	nm_assert (c_list_contains (&NM_FIREWALL_MANAGER_GET_PRIVATE (call_id->self)->pending_calls, &call_id->lst));

	self = call_id->self;

	_LOGD (call_id, "complete: fake success");

	call_id->idle.id = 0;

	_cb_info_complete (call_id, NULL);
	return G_SOURCE_REMOVE;
}

static gboolean
_handle_idle_start (NMFirewallManager *self,
                    NMFirewallManagerCallId *call_id)
{
	if (!call_id->callback) {
		/* if the user did not provide a callback and firewalld is not running,
		 * there is no point in scheduling an idle-request to fake success. Just
		 * return right away. */
		_LOGD (call_id, "complete: drop request simulating success");
		_cb_info_complete (call_id, NULL);
		return FALSE;
	}
	call_id->idle.id = g_idle_add (_handle_idle_cb, call_id);
	return TRUE;
}

static void
_handle_dbus_cb (GObject *source,
                 GAsyncResult *result,
                 gpointer user_data)
{
	NMFirewallManager *self;
	NMFirewallManagerCallId *call_id;
	gs_free_error GError *error = NULL;
	gs_unref_variant GVariant *ret = NULL;

	ret = g_dbus_connection_call_finish (G_DBUS_CONNECTION (source), result, &error);

	if (   !ret
	    && nm_utils_error_is_cancelled (error))
		return;

	call_id = user_data;

	nm_assert (call_id);
	nm_assert (NM_IS_FIREWALL_MANAGER (call_id->self));
	nm_assert (!call_id->is_idle);
	nm_assert (c_list_contains (&NM_FIREWALL_MANAGER_GET_PRIVATE (call_id->self)->pending_calls, &call_id->lst));

	self = call_id->self;

	if (error) {
		const char *non_error = NULL;

		g_dbus_error_strip_remote_error (error);

		switch (call_id->ops_type) {
		case OPS_TYPE_ADD:
		case OPS_TYPE_CHANGE:
			non_error = "ZONE_ALREADY_SET";
			break;
		case OPS_TYPE_REMOVE:
			non_error = "UNKNOWN_INTERFACE";
			break;
		}
		if (   error->message
		    && non_error
		    && g_str_has_prefix (error->message, non_error)
		    && NM_IN_SET (error->message[strlen (non_error)], '\0', ':')) {
			_LOGD (call_id, "complete: request failed with a non-error (%s)", error->message);

			/* The operation failed with an error reason that we don't want
			 * to propagate. Instead, signal success. */
			g_clear_error (&error);
		} else
			_LOGW (call_id, "complete: request failed (%s)", error->message);
	} else
		_LOGD (call_id, "complete: success");

	g_clear_object (&call_id->dbus.cancellable);

	_cb_info_complete (call_id, error);
}

static void
_handle_dbus_start (NMFirewallManager *self,
                    NMFirewallManagerCallId *call_id)
{
	NMFirewallManagerPrivate *priv = NM_FIREWALL_MANAGER_GET_PRIVATE (self);
	const char *dbus_method = NULL;
	GVariant *arg;

	nm_assert (call_id);
	nm_assert (priv->running);
	nm_assert (!call_id->is_idle);
	nm_assert (c_list_contains (&priv->pending_calls, &call_id->lst));

	switch (call_id->ops_type) {
	case OPS_TYPE_ADD:
		dbus_method = "addInterface";
		break;
	case OPS_TYPE_CHANGE:
		dbus_method = "changeZone";
		break;
	case OPS_TYPE_REMOVE:
		dbus_method = "removeInterface";
		break;
	}
	nm_assert (dbus_method);

	arg = g_steal_pointer (&call_id->dbus.arg);

	nm_assert (arg && g_variant_is_floating (arg));

	nm_assert (!call_id->dbus.cancellable);

	call_id->dbus.cancellable = g_cancellable_new ();

	g_dbus_connection_call (priv->dbus_connection,
	                        FIREWALL_DBUS_SERVICE,
	                        FIREWALL_DBUS_PATH,
	                        FIREWALL_DBUS_INTERFACE_ZONE,
	                        dbus_method,
	                        arg,
	                        NULL,
	                        G_DBUS_CALL_FLAGS_NONE,
	                        10000,
	                        call_id->dbus.cancellable,
	                        _handle_dbus_cb,
	                        call_id);
}

static NMFirewallManagerCallId *
_start_request (NMFirewallManager *self,
                OpsType ops_type,
                const char *iface,
                const char *zone,
                NMFirewallManagerAddRemoveCallback callback,
                gpointer user_data)
{
	NMFirewallManagerPrivate *priv;
	NMFirewallManagerCallId *call_id;

	g_return_val_if_fail (NM_IS_FIREWALL_MANAGER (self), NULL);
	g_return_val_if_fail (iface && *iface, NULL);

	priv = NM_FIREWALL_MANAGER_GET_PRIVATE (self);

	call_id = _cb_info_create (self, ops_type, iface, zone, callback, user_data);

	_LOGD (call_id, "firewall zone %s %s:%s%s%s%s",
	       _ops_type_to_string (call_id->ops_type),
	       iface,
	       NM_PRINT_FMT_QUOTED (zone, "\"", zone, "\"", "default"),
	       call_id->is_idle
	         ? " (not running, simulate success)"
	         : (!priv->running
	              ? " (waiting to initialize)"
	              : ""));

	if (!call_id->is_idle) {
		if (priv->running)
			_handle_dbus_start (self, call_id);
		if (!call_id->callback) {
			/* if the user did not provide a callback, the call_id is useless.
			 * Especially, the user cannot use the call-id to cancel the request,
			 * because he cannot know whether the request is still pending.
			 *
			 * Hence, returning %NULL doesn't mean that the request could not be started
			 * (this function never fails and always starts a request). */
			return NULL;
		}
	} else {
		if (!_handle_idle_start (self, call_id)) {
			/* if the user did not provide a callback and firewalld is not running,
			 * there is no point in scheduling an idle-request to fake success. Just
			 * return right away. */
			return NULL;
		}
	}

	return call_id;
}

NMFirewallManagerCallId *
nm_firewall_manager_add_or_change_zone (NMFirewallManager *self,
                                        const char *iface,
                                        const char *zone,
                                        gboolean add, /* TRUE == add, FALSE == change */
                                        NMFirewallManagerAddRemoveCallback callback,
                                        gpointer user_data)
{
	return _start_request (self,
	                       add ? OPS_TYPE_ADD : OPS_TYPE_CHANGE,
	                       iface,
	                       zone,
	                       callback,
	                       user_data);
}

NMFirewallManagerCallId *
nm_firewall_manager_remove_from_zone (NMFirewallManager *self,
                                      const char *iface,
                                      const char *zone,
                                      NMFirewallManagerAddRemoveCallback callback,
                                      gpointer user_data)
{
	return _start_request (self,
	                       OPS_TYPE_REMOVE,
	                       iface,
	                       zone,
	                       callback,
	                       user_data);
}

void
nm_firewall_manager_cancel_call (NMFirewallManagerCallId *call_id)
{
	NMFirewallManager *self;
	NMFirewallManagerPrivate *priv;
	gs_free_error GError *error = NULL;

	g_return_if_fail (call_id);
	g_return_if_fail (NM_IS_FIREWALL_MANAGER (call_id->self));
	g_return_if_fail (!c_list_is_empty (&call_id->lst));

	self = call_id->self;
	priv = NM_FIREWALL_MANAGER_GET_PRIVATE (self);

	nm_assert (c_list_contains (&priv->pending_calls, &call_id->lst));

	nm_utils_error_set_cancelled (&error, FALSE, "NMFirewallManager");

	_LOGD (call_id, "complete: cancel (%s)", error->message);

	_cb_info_complete (call_id, error);
}

/*****************************************************************************/

static void
name_owner_changed (NMFirewallManager *self,
                    const char *owner)
{
	_nm_unused gs_unref_object NMFirewallManager *self_keep_alive = g_object_ref (self);
	NMFirewallManagerPrivate *priv = NM_FIREWALL_MANAGER_GET_PRIVATE (self);
	gboolean was_running;
	gboolean now_running;
	gboolean just_initied;

	owner = nm_str_not_empty (owner);

	if (!owner)
		_LOGT (NULL, "D-Bus name for firewalld has no owner (firewall stopped)");
	else
		_LOGT (NULL, "D-Bus name for firewalld has owner %s (firewall started)", owner);

	was_running = _get_running (priv);
	just_initied = !priv->dbus_inited;

	priv->dbus_inited = TRUE;
	priv->running = !!owner;

	now_running = _get_running (priv);

	if (just_initied) {
		NMFirewallManagerCallId *call_id_safe;
		NMFirewallManagerCallId *call_id;

		/* We kick of the requests that we have pending. Note that this is
		 * entirely asynchronous and also we don't invoke any callbacks for
		 * the user.
		 * Even _handle_idle_start() just schedules an idle handler. That is,
		 * because we don't want to callback to the user before emitting the
		 * DISCONNECTED signal below. Also, emitting callbacks means the user
		 * can call back to modify the list of pending-calls and we'd have
		 * to handle reentrancy. */
		c_list_for_each_entry_safe (call_id, call_id_safe, &priv->pending_calls, lst) {

			nm_assert (!call_id->is_idle);
			nm_assert (call_id->dbus.arg);

			if (priv->running) {
				_LOGD (call_id, "initalizing: make D-Bus call");
				_handle_dbus_start (self, call_id);
			} else {
				/* we don't want to invoke callbacks to the user right away. That is because
				 * the user might schedule/cancel more calls, which messes up the order.
				 *
				 * Instead, convert the pending calls to idle requests... */
				nm_clear_pointer (&call_id->dbus.arg, g_variant_unref);
				call_id->is_idle = TRUE;
				_LOGD (call_id, "initializing: fake success on idle");
				_handle_idle_start (self, call_id);
			}
		}
	}

	if (was_running != now_running)
		g_signal_emit (self, signals[STATE_CHANGED], 0, FALSE);
}

static void
name_owner_changed_cb (GDBusConnection *connection,
                       const char *sender_name,
                       const char *object_path,
                       const char *interface_name,
                       const char *signal_name,
                       GVariant *parameters,
                       gpointer user_data)
{
	NMFirewallManager *self = user_data;
	const char *new_owner;

	if (!g_variant_is_of_type (parameters, G_VARIANT_TYPE ("(sss)")))
		return;

	g_variant_get (parameters,
	               "(&s&s&s)",
	               NULL,
	               NULL,
	               &new_owner);

	name_owner_changed (self, new_owner);
}

static void
get_name_owner_cb (const char *name_owner,
                   GError *error,
                   gpointer user_data)
{
	NMFirewallManager *self;
	NMFirewallManagerPrivate *priv;

	if (   !name_owner
	    && g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
		return;

	self = user_data;
	priv = NM_FIREWALL_MANAGER_GET_PRIVATE (self);

	g_clear_object (&priv->get_name_owner_cancellable);

	name_owner_changed (self, name_owner);
}

/*****************************************************************************/

static void
nm_firewall_manager_init (NMFirewallManager *self)
{
	NMFirewallManagerPrivate *priv = NM_FIREWALL_MANAGER_GET_PRIVATE (self);

	c_list_init (&priv->pending_calls);

	priv->dbus_connection = nm_g_object_ref (NM_MAIN_DBUS_CONNECTION_GET);

	if (!priv->dbus_connection) {
		_LOGD (NULL, "no D-Bus connection");
		return;
	}

	priv->name_owner_changed_id = nm_dbus_connection_signal_subscribe_name_owner_changed (priv->dbus_connection,
	                                                                                      FIREWALL_DBUS_SERVICE,
	                                                                                      name_owner_changed_cb,
	                                                                                      self,
	                                                                                      NULL);

	priv->get_name_owner_cancellable = g_cancellable_new ();
	nm_dbus_connection_call_get_name_owner (priv->dbus_connection,
	                                        FIREWALL_DBUS_SERVICE,
	                                        -1,
	                                        priv->get_name_owner_cancellable,
	                                        get_name_owner_cb,
	                                        self);
}

static void
dispose (GObject *object)
{
	NMFirewallManager *self = NM_FIREWALL_MANAGER (object);
	NMFirewallManagerPrivate *priv = NM_FIREWALL_MANAGER_GET_PRIVATE (self);

	/* as every pending operation takes a reference to the manager,
	 * we don't expect pending operations at this point. */
	nm_assert (c_list_is_empty (&priv->pending_calls));

	nm_clear_g_dbus_connection_signal (priv->dbus_connection,
	                                   &priv->name_owner_changed_id);

	nm_clear_g_cancellable (&priv->get_name_owner_cancellable);

	G_OBJECT_CLASS (nm_firewall_manager_parent_class)->dispose (object);

	g_clear_object (&priv->dbus_connection);
}

static void
nm_firewall_manager_class_init (NMFirewallManagerClass *klass)
{
	GObjectClass *object_class = G_OBJECT_CLASS (klass);

	object_class->dispose = dispose;

	signals[STATE_CHANGED] =
	    g_signal_new (NM_FIREWALL_MANAGER_STATE_CHANGED,
	                  G_OBJECT_CLASS_TYPE (object_class),
	                  G_SIGNAL_RUN_FIRST,
	                  0,
	                  NULL, NULL,
	                  g_cclosure_marshal_VOID__BOOLEAN,
	                  G_TYPE_NONE, 1,
	                  G_TYPE_BOOLEAN /* initialized_now */);
}