// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2007-2014 Nicira, Inc.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/if.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/if_tunnel.h>
#include <linux/if_vlan.h>
#include <linux/in.h>
#include <linux/in_route.h>
#include <linux/inetdevice.h>
#include <linux/jhash.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/workqueue.h>
#include <linux/rculist.h>
#include <net/route.h>
#include <net/xfrm.h>

#include <net/icmp.h>
#include <net/ip.h>
#include <net/ip_tunnels.h>
#include <net/gre.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/protocol.h>

#include "datapath.h"
#include "vport.h"
#include "vport-netdev.h"

static struct vport_ops ovs_gre_vport_ops;

static struct vport *gre_tnl_create(const struct vport_parms *parms)
{
        struct net *net = ovs_dp_get_net(parms->dp);
        struct net_device *dev;
        struct vport *vport;
        int err;

        vport = ovs_vport_alloc(0, &ovs_gre_vport_ops, parms);
        if (IS_ERR(vport))
                return vport;

        rtnl_lock();
        dev = gretap_fb_dev_create(net, parms->name, NET_NAME_USER);
        if (IS_ERR(dev)) {
                rtnl_unlock();
                ovs_vport_free(vport);
                return ERR_CAST(dev);
        }

        err = dev_change_flags(dev, dev->flags | IFF_UP, NULL);
        if (err < 0) {
                rtnl_delete_link(dev, 0, NULL);
                rtnl_unlock();
                ovs_vport_free(vport);
                return ERR_PTR(err);
        }

        rtnl_unlock();
        return vport;
}

static struct vport *gre_create(const struct vport_parms *parms)
{
        struct vport *vport;

        vport = gre_tnl_create(parms);
        if (IS_ERR(vport))
                return vport;

        return ovs_netdev_link(vport, parms->name);
}

static struct vport_ops ovs_gre_vport_ops = {
        .type           = OVS_VPORT_TYPE_GRE,
        .create         = gre_create,
        .send           = dev_queue_xmit,
        .destroy        = ovs_netdev_tunnel_destroy,
};

static int __init ovs_gre_tnl_init(void)
{
        return ovs_vport_ops_register(&ovs_gre_vport_ops);
}

static void __exit ovs_gre_tnl_exit(void)
{
        ovs_vport_ops_unregister(&ovs_gre_vport_ops);
}

module_init(ovs_gre_tnl_init);
module_exit(ovs_gre_tnl_exit);

MODULE_DESCRIPTION("OVS: GRE switching port");
MODULE_LICENSE("GPL");
MODULE_ALIAS("vport-type-3");