NetworkManager/src/systemd/nm-sd.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2014 - 2016 Red Hat, Inc.
 */

#include "nm-default.h"

#include "nm-sd.h"

#include "sd-event.h"

/*****************************************************************************
 * Integrating sd_event into glib. Taken and adjusted from
 * https://www.freedesktop.org/software/systemd/man/sd_event_get_fd.html
 *****************************************************************************/

typedef struct SDEventSource {
	GSource source;
	GPollFD pollfd;
	sd_event *event;
} SDEventSource;

static gboolean
event_prepare (GSource *source, int *timeout_)
{
	return sd_event_prepare (((SDEventSource *) source)->event) > 0;
}

static gboolean
event_check (GSource *source)
{
	return sd_event_wait (((SDEventSource *) source)->event, 0) > 0;
}

static gboolean
event_dispatch (GSource *source, GSourceFunc callback, gpointer user_data)
{
	return sd_event_dispatch (((SDEventSource *) source)->event) > 0;
}

static void
event_finalize (GSource *source)
{
	SDEventSource *s = (SDEventSource *) source;

	sd_event_unref (s->event);
}

static SDEventSource *
event_create_source (sd_event *event)
{
	static const GSourceFuncs event_funcs = {
		.prepare = event_prepare,
		.check = event_check,
		.dispatch = event_dispatch,
		.finalize = event_finalize,
	};
	SDEventSource *source;
	gboolean is_default_event = FALSE;
	int r;

	if (!event) {
		is_default_event = TRUE;
		r = sd_event_default (&event);
		if (r < 0)
			g_return_val_if_reached (NULL);
	}

	source = (SDEventSource *) g_source_new ((GSourceFuncs *) &event_funcs, sizeof (SDEventSource));

	source->event =   is_default_event
	                ? g_steal_pointer (&event)
	                : sd_event_ref (event);

	source->pollfd = (GPollFD) {
	    .fd     = sd_event_get_fd (source->event),
	    .events = G_IO_IN | G_IO_HUP | G_IO_ERR,
	};

	g_source_add_poll (&source->source, &source->pollfd);

	return source;
}

static guint
event_attach (sd_event *event, GMainContext *context)
{
	SDEventSource *source;
	guint id;

	source = event_create_source (event);

	g_return_val_if_fail (source, 0);

	id = g_source_attach ((GSource *) source, context);
	g_source_unref ((GSource *) source);

	nm_assert (id != 0);
	return id;
}

guint
nm_sd_event_attach_default (void)
{
	return event_attach (NULL, NULL);
}

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

/* ensure that defines in nm-sd.h correspond to the internal defines. */

#include "nm-sd-adapt-core.h"
#include "dhcp-lease-internal.h"

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