NetworkManager/src/core/nm-dbus-object.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2018 Red Hat, Inc.
 */

#ifndef __NM_DBUS_OBJECT_H__
#define __NM_DBUS_OBJECT_H__

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

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

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

typedef struct {
    const char *path;

    /* if path is of type NM_DBUS_EXPORT_PATH_NUMBERED(), we need a
     * per-class counter when generating a new numbered path.
     *
     * Each NMDBusObjectClass instance has a shallow clone of the NMDBusObjectClass parent
     * instance in every derived type. Hence we cannot embed the counter there directly,
     * because it must be shared, e.g. between NMDeviceBond and NMDeviceEthernet.
     * Make int_counter a pointer to the actual counter that is used by ever sibling
     * class. */
    long long unsigned *int_counter;
} NMDBusExportPath;

#define NM_DBUS_EXPORT_PATH_STATIC(basepath) \
    ({                                       \
        ((NMDBusExportPath) {                \
            .path = "" basepath "",          \
        });                                  \
    })

#define NM_DBUS_EXPORT_PATH_NUMBERED(basepath)      \
    ({                                              \
        static long long unsigned _int_counter = 0; \
        ((NMDBusExportPath) {                       \
            .path        = "" basepath "/%llu",     \
            .int_counter = &_int_counter,           \
        });                                         \
    })

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

#define NM_TYPE_DBUS_OBJECT (nm_dbus_object_get_type())
#define NM_DBUS_OBJECT(obj) \
    (_NM_G_TYPE_CHECK_INSTANCE_CAST((obj), NM_TYPE_DBUS_OBJECT, NMDBusObject))
#define NM_DBUS_OBJECT_CLASS(klass) \
    (G_TYPE_CHECK_CLASS_CAST((klass), NM_TYPE_DBUS_OBJECT, NMDBusObjectClass))
#define NM_IS_DBUS_OBJECT(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), NM_TYPE_DBUS_OBJECT))
#define NM_IS_DBUS_OBJECT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), NM_TYPE_DBUS_OBJECT))
#define NM_DBUS_OBJECT_GET_CLASS(obj) \
    (G_TYPE_INSTANCE_GET_CLASS((obj), NM_TYPE_DBUS_OBJECT, NMDBusObjectClass))

#define NM_DBUS_OBJECT_EXPORTED_CHANGED "exported-changed"

/* NMDBusObject and NMDBusManager cooperate strongly. Hence, there is an
 * internal data structure attached to the NMDBusObject accessible to both of them. */
struct _NMDBusObjectInternal {
    char          *path;
    NMDBusManager *bus_manager;
    CList          objects_lst;
    CList          registration_lst_head;

    /* we perform asynchronous operation on exported objects. For example, we receive
     * a Set property call, and asynchronously validate the operation. We must make
     * sure that when the authentication is complete, that we are still looking at
     * the same (exported) object. In the meantime, the object could have been
     * unexported, or even re-exported afterwards. If that happens, we want
     * to fail the request. For that, we keep track of a version id.  */
    guint64 export_version_id;
    bool    is_unexporting : 1;
};

struct _NMDBusObject {
    GObject                      parent;
    struct _NMDBusObjectInternal internal;
};

#define NM_DEFINE_DBUS_INTERFACE_INFO(...) \
    ((NMDBusInterfaceInfo *) (&((const NMDBusInterfaceInfo) {__VA_ARGS__})))

typedef struct {
    GObjectClass parent;

    NMDBusExportPath export_path;

    const NMDBusInterfaceInfoExtended *const *interface_infos;

    bool export_on_construction;
} NMDBusObjectClass;

GType nm_dbus_object_get_type(void);

static inline NMDBusManager *
nm_dbus_object_get_manager(NMDBusObject *obj)
{
    nm_assert(NM_IS_DBUS_OBJECT(obj));

    return obj->internal.bus_manager;
}

static inline guint64
nm_dbus_object_get_export_version_id(NMDBusObject *obj)
{
    nm_assert(NM_IS_DBUS_OBJECT(obj));

    return obj->internal.export_version_id;
}

/**
 * nm_dbus_object_get_path:
 * @self: an #NMDBusObject
 *
 * Gets @self's D-Bus path.
 *
 * Returns: @self's D-Bus path, or %NULL if @self is not exported.
 */
static inline const char *
nm_dbus_object_get_path(NMDBusObject *self)
{
    g_return_val_if_fail(NM_IS_DBUS_OBJECT(self), NULL);

    return self->internal.path;
}

/**
 * nm_dbus_object_is_exported:
 * @self: an #NMDBusObject
 *
 * Checks if @self is exported
 *
 * Returns: %TRUE if @self is exported
 */
static inline gboolean
nm_dbus_object_is_exported(NMDBusObject *self)
{
    return !!nm_dbus_object_get_path(self);
}

static inline const char *
nm_dbus_object_get_path_still_exported(NMDBusObject *self)
{
    g_return_val_if_fail(NM_IS_DBUS_OBJECT(self), NULL);

    /* like nm_dbus_object_get_path(), however, while unexporting
     * (exported-changed signal), returns %NULL instead of the path. */
    return self->internal.is_unexporting ? NULL : self->internal.path;
}

const char *nm_dbus_object_export(gpointer /* (NMDBusObject *) */ self);
void        nm_dbus_object_unexport(gpointer /* (NMDBusObject *) */ self);

void nm_dbus_object_unexport_on_idle(gpointer /* (NMDBusObject *) */ self_take);

gboolean _nm_dbus_object_clear_and_unexport(NMDBusObject **location);
#define nm_dbus_object_clear_and_unexport(location) \
    _nm_dbus_object_clear_and_unexport(NM_CAST_PPTR(NMDBusObject, (location)))

void nm_dbus_object_emit_signal_variant(NMDBusObject                      *self,
                                        const NMDBusInterfaceInfoExtended *interface_info,
                                        const GDBusSignalInfo             *signal_info,
                                        GVariant                          *args);

void nm_dbus_object_emit_signal(NMDBusObject                      *self,
                                const NMDBusInterfaceInfoExtended *interface_info,
                                const GDBusSignalInfo             *signal_info,
                                const char                        *format,
                                ...);

#endif /* __NM_DBUS_OBJECT_H__ */