/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
/* 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, or (at your option)
 * any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Copyright (C) 2010 Red Hat, Inc.
 */

#ifndef NM_DNS_PLUGIN_H
#define NM_DNS_PLUGIN_H

#include <glib.h>
#include <glib-object.h>

#define NM_TYPE_DNS_PLUGIN            (nm_dns_plugin_get_type ())
#define NM_DNS_PLUGIN(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), NM_TYPE_DNS_PLUGIN, NMDnsPlugin))
#define NM_DNS_PLUGIN_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), NM_TYPE_DNS_PLUGIN, NMDnsPluginClass))
#define NM_IS_DNS_PLUGIN(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), NM_TYPE_DNS_PLUGIN))
#define NM_IS_DNS_PLUGIN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((obj), NM_TYPE_DNS_PLUGIN))
#define NM_DNS_PLUGIN_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), NM_TYPE_DNS_PLUGIN, NMDnsPluginClass))

#define NM_DNS_PLUGIN_FAILED "failed"
#define NM_DNS_PLUGIN_CHILD_QUIT "child-quit"

typedef struct {
	GObject parent;
} NMDnsPlugin;

typedef struct {
	GObjectClass parent;

	/* Methods */
	gboolean (*init) (NMDnsPlugin *self);

	/* Called when DNS information is changed.  'vpn_configs' is a list of
	 * NMIP4Config or NMIP6Config objects from VPN connections, while
	 * 'dev_configs' is a list of NMPI4Config or NMIP6Config objects from
	 * active devices.  'other_configs' represent other IP configuration that
	 * may be in-use.  Configs of the same IP version are sorted in priority
	 * order.
	 */
	gboolean (*update) (NMDnsPlugin *self,
	                    const GSList *vpn_configs,
	                    const GSList *dev_configs,
	                    const GSList *other_configs,
	                    const char *hostname,
	                    const char *iface);

	/* Subclasses should override and return TRUE if they start a local
	 * caching nameserver that listens on localhost and would block any
	 * other local caching nameserver from operating.
	 */
	gboolean (*is_caching) (NMDnsPlugin *self);

	/* Subclasses should override this and return their plugin name */
	const char *(*get_name) (NMDnsPlugin *self);

	/* Signals */

	/* Emitted by the plugin and consumed by NMDnsManager when
	 * some error happens with the nameserver subprocess.  Causes NM to fall
	 * back to writing out a non-local-caching resolv.conf until the next
	 * DNS update.
	 */
	void (*failed) (NMDnsPlugin *self);

	/* Emitted by the plugin base class when the nameserver subprocess
	 * quits.  This signal is consumed by the plugin subclasses and not
	 * by NMDnsManager.  If the subclass decides the exit status (as returned
	 * by waitpid(2)) is fatal it should then emit the 'failed' signal.
	 */
	void (*child_quit) (NMDnsPlugin *self, gint status);
} NMDnsPluginClass;

GType nm_dns_plugin_get_type (void);

gboolean nm_dns_plugin_is_caching (NMDnsPlugin *self);

const char *nm_dns_plugin_get_name (NMDnsPlugin *self);

gboolean nm_dns_plugin_update (NMDnsPlugin *self,
                               const GSList *vpn_configs,
                               const GSList *dev_configs,
                               const GSList *other_configs,
                               const char *hostname,
                               const char *iface);

/* For subclasses/plugins */

/* Spawn a child process and watch for it to quit.  'argv' is the NULL-terminated
 * argument vector to spawn the child with, where argv[0] is the full path to
 * the child's executable.  If 'pidfile' is given the process owning the PID
 * contained in 'pidfile' will be killed if its command line matches 'kill_match'
 * and the pidfile will be deleted.
 */
GPid nm_dns_plugin_child_spawn (NMDnsPlugin *self,
                                const char **argv,
                                const char *pidfile,
                                const char *kill_match);

gboolean nm_dns_plugin_child_kill (NMDnsPlugin *self);

#endif /* NM_DNS_PLUGIN_H */

