// SPDX-License-Identifier: GPL-2.0+

/*

 * Copyright (C) 2008 Roy Marples

 * Copyright (C) 2010 Dan Williams <dcbw@redhat.com>

 */

#include "nm-default.h"

#if WITH_DHCPCD

#include <stdlib.h>

#include <unistd.h>

#include <stdio.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include "nm-dhcp-manager.h"

#include "nm-utils.h"

#include "NetworkManagerUtils.h"

#include "nm-dhcp-listener.h"

#include "nm-dhcp-client-logging.h"

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

#define NM_TYPE_DHCP_DHCPCD            (nm_dhcp_dhcpcd_get_type ())

#define NM_DHCP_DHCPCD(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), NM_TYPE_DHCP_DHCPCD, NMDhcpDhcpcd))

#define NM_DHCP_DHCPCD_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), NM_TYPE_DHCP_DHCPCD, NMDhcpDhcpcdClass))

#define NM_IS_DHCP_DHCPCD(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), NM_TYPE_DHCP_DHCPCD))

#define NM_IS_DHCP_DHCPCD_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), NM_TYPE_DHCP_DHCPCD))

#define NM_DHCP_DHCPCD_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), NM_TYPE_DHCP_DHCPCD, NMDhcpDhcpcdClass))

typedef struct _NMDhcpDhcpcd NMDhcpDhcpcd;

typedef struct _NMDhcpDhcpcdClass NMDhcpDhcpcdClass;

static GType nm_dhcp_dhcpcd_get_type (void);

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

typedef struct {

	char *pid_file;

	NMDhcpListener *dhcp_listener;

} NMDhcpDhcpcdPrivate;

struct _NMDhcpDhcpcd {

	NMDhcpClient parent;

	NMDhcpDhcpcdPrivate _priv;

};

struct _NMDhcpDhcpcdClass {

	NMDhcpClientClass parent;

};

G_DEFINE_TYPE (NMDhcpDhcpcd, nm_dhcp_dhcpcd, NM_TYPE_DHCP_CLIENT)

#define NM_DHCP_DHCPCD_GET_PRIVATE(self) _NM_GET_PRIVATE (self, NMDhcpDhcpcd, NM_IS_DHCP_DHCPCD)

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

static const char *

nm_dhcp_dhcpcd_get_path (void)

{

	return nm_utils_find_helper ("dhcpcd", DHCPCD_PATH, NULL);

}

static gboolean

ip4_start (NMDhcpClient *client,

           const char *dhcp_anycast_addr,

           const char *last_ip4_address,

           GError **error)

{

	NMDhcpDhcpcd *self = NM_DHCP_DHCPCD (client);

	NMDhcpDhcpcdPrivate *priv = NM_DHCP_DHCPCD_GET_PRIVATE (self);

	gs_unref_ptrarray GPtrArray *argv = NULL;

	pid_t pid = -1;

	GError *local = NULL;

	gs_free char *cmd_str = NULL;

	gs_free char *binary_name = NULL;

	const char *iface;

	const char *dhcpcd_path;

	const char *hostname;

	g_return_val_if_fail (priv->pid_file == NULL, FALSE);

	iface = nm_dhcp_client_get_iface (client);

	/* dhcpcd does not allow custom pidfiles; the pidfile is always

	 * RUNSTATEDIR "dhcpcd-<ifname>.pid".

	 */

	priv->pid_file = g_strdup_printf (RUNSTATEDIR "/dhcpcd-%s.pid", iface);

	dhcpcd_path = nm_dhcp_dhcpcd_get_path ();

	if (!dhcpcd_path) {

		nm_utils_error_set_literal (error, NM_UTILS_ERROR_UNKNOWN, "dhcpcd binary not found");

		return FALSE;

	}

	/* Kill any existing dhcpcd from the pidfile */

	binary_name = g_path_get_basename (dhcpcd_path);

	nm_dhcp_client_stop_existing (priv->pid_file, binary_name);

	argv = g_ptr_array_new ();

	g_ptr_array_add (argv, (gpointer) dhcpcd_path);

	g_ptr_array_add (argv, (gpointer) "-B");    /* Don't background on lease (disable fork()) */

	g_ptr_array_add (argv, (gpointer) "-K");    /* Disable built-in carrier detection */

	g_ptr_array_add (argv, (gpointer) "-L");    /* Disable built-in IPv4LL */

	/* --noarp. Don't request or claim the address by ARP; this also disables IPv4LL. */

	g_ptr_array_add (argv, (gpointer) "-A");

	g_ptr_array_add (argv, (gpointer) "-G");    /* Let NM handle routing */

	g_ptr_array_add (argv, (gpointer) "-c");    /* Set script file */

	g_ptr_array_add (argv, (gpointer) nm_dhcp_helper_path);

	/* IPv4-only for now.  NetworkManager knows better than dhcpcd when to

	 * run IPv6, and dhcpcd's automatic Router Solicitations cause problems

	 * with devices that don't expect them.

	 */

	g_ptr_array_add (argv, (gpointer) "-4");

	hostname = nm_dhcp_client_get_hostname (client);

	if (hostname) {

		if (nm_dhcp_client_get_use_fqdn (client)) {

			g_ptr_array_add (argv, (gpointer) "-h");

			g_ptr_array_add (argv, (gpointer) hostname);

			g_ptr_array_add (argv, (gpointer) "-F");

			g_ptr_array_add (argv, (gpointer) "both");

		} else {

			g_ptr_array_add (argv, (gpointer) "-h");

			g_ptr_array_add (argv, (gpointer) hostname);

		}

	}

	g_ptr_array_add (argv, (gpointer) iface);

	g_ptr_array_add (argv, NULL);

	_LOGD ("running: %s",

	       (cmd_str = g_strjoinv (" ", (char **) argv->pdata)));

	if (!g_spawn_async (NULL,

	                    (char **) argv->pdata, NULL,

	                      G_SPAWN_DO_NOT_REAP_CHILD

	                    | G_SPAWN_STDOUT_TO_DEV_NULL

	                    | G_SPAWN_STDERR_TO_DEV_NULL,

	                    nm_utils_setpgid,

	                    NULL,

	                    &pid,

	                    &local)) {

		nm_utils_error_set (error,

		                    NM_UTILS_ERROR_UNKNOWN,

		                    "dhcpcd failed to start: %s",

		                    local->message);

		g_error_free (local);

		return FALSE;

	}

	nm_assert (pid > 0);

	_LOGI ("dhcpcd started with pid %d", pid);

	nm_dhcp_client_watch_child (client, pid);

	return TRUE;

}

static void

stop (NMDhcpClient *client, gboolean release)

{

	NMDhcpDhcpcd *self = NM_DHCP_DHCPCD (client);

	NMDhcpDhcpcdPrivate *priv = NM_DHCP_DHCPCD_GET_PRIVATE (self);

	int errsv;

	NM_DHCP_CLIENT_CLASS (nm_dhcp_dhcpcd_parent_class)->stop (client, release);

	if (priv->pid_file) {

		if (remove (priv->pid_file) == -1) {

			errsv = errno;

			_LOGD ("could not remove dhcp pid file \"%s\": %d (%s)", priv->pid_file, errsv, nm_strerror_native (errsv));

		}

	}

	/* FIXME: implement release... */

}

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

static void

nm_dhcp_dhcpcd_init (NMDhcpDhcpcd *self)

{

	NMDhcpDhcpcdPrivate *priv = NM_DHCP_DHCPCD_GET_PRIVATE (self);

	priv->dhcp_listener = g_object_ref (nm_dhcp_listener_get ());

	g_signal_connect (priv->dhcp_listener,

	                  NM_DHCP_LISTENER_EVENT,

	                  G_CALLBACK (nm_dhcp_client_handle_event),

	                  self);

}

static void

dispose (GObject *object)

{

	NMDhcpDhcpcdPrivate *priv = NM_DHCP_DHCPCD_GET_PRIVATE (object);

	if (priv->dhcp_listener) {

		g_signal_handlers_disconnect_by_func (priv->dhcp_listener,

		                                      G_CALLBACK (nm_dhcp_client_handle_event),

		                                      NM_DHCP_DHCPCD (object));

		g_clear_object (&priv->dhcp_listener);

	}

	nm_clear_g_free (&priv->pid_file);

	G_OBJECT_CLASS (nm_dhcp_dhcpcd_parent_class)->dispose (object);

}

static void

nm_dhcp_dhcpcd_class_init (NMDhcpDhcpcdClass *dhcpcd_class)

{

	NMDhcpClientClass *client_class = NM_DHCP_CLIENT_CLASS (dhcpcd_class);

	GObjectClass *object_class = G_OBJECT_CLASS (dhcpcd_class);

	object_class->dispose = dispose;

	client_class->ip4_start = ip4_start;

	client_class->stop = stop;

}

const NMDhcpClientFactory _nm_dhcp_client_factory_dhcpcd = {

	.name     = "dhcpcd",

	.get_type = nm_dhcp_dhcpcd_get_type,

	.get_path = nm_dhcp_dhcpcd_get_path,

};

#endif /* WITH_DHCPCD */