// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2007-2012 Nicira, Inc.
 */

/*
 * Includes Inango Systems Ltd’s changes/modifications dated: 2021.
 * Changed/modified portions - Copyright (c) 2021 , Inango Systems Ltd.
 */

/*
  Includes MaxLinear's changes dated: 2021, 2022, 2023.
  Changed portions - Copyright 2021-2023 MaxLinear, Inc.
*/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/if_arp.h>
#include <linux/if_bridge.h>
#include <linux/if_vlan.h>
#include <linux/kernel.h>
#include <linux/llc.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/openvswitch.h>
#include <linux/export.h>

#include <net/ip_tunnels.h>
#include <net/rtnetlink.h>

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

static struct vport_ops ovs_netdev_vport_ops;

/* Must be called with rcu_read_lock. */
static void netdev_port_receive(struct sk_buff *skb)
{
	struct vport *vport;

	vport = ovs_netdev_get_vport(skb->dev);
	if (unlikely(!vport))
		goto error;

	if (unlikely(skb_warn_if_lro(skb)))
		goto error;

	/* Make our own copy of the packet.  Otherwise we will mangle the
	 * packet for anyone who came before us (e.g. tcpdump via AF_PACKET).
	 */
	skb = skb_share_check(skb, GFP_ATOMIC);
	if (unlikely(!skb))
		return;

	if (skb->dev->type == ARPHRD_ETHER)
		skb_push_rcsum(skb, ETH_HLEN);

	ovs_vport_receive(vport, skb, skb_tunnel_info(skb));
	return;
error:
	kfree_skb(skb);
}

/* Called with rcu_read_lock and bottom-halves disabled. */
static rx_handler_result_t netdev_frame_hook(struct sk_buff **pskb)
{
	struct sk_buff *skb = *pskb;

	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
		return RX_HANDLER_PASS;

	netdev_port_receive(skb);
	return RX_HANDLER_CONSUMED;
}

static struct net_device *get_dpdev(const struct datapath *dp)
{
	struct vport *local;

	local = ovs_vport_ovsl(dp, OVSP_LOCAL);
	BUG_ON(!local);
	return local->dev;
}
#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
struct vport *ovs_netdev_link(struct vport *vport, const char *name, const char *bridgeName)
#else
struct vport *ovs_netdev_link(struct vport *vport, const char *name)
#endif
{
	int err;
#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
	struct vport *bridge = NULL;
#endif

	vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), name);
	if (!vport->dev) {
		err = -ENODEV;
		goto error_free_vport;
	}

	if (vport->dev->flags & IFF_LOOPBACK ||
	    (vport->dev->type != ARPHRD_ETHER &&
	     vport->dev->type != ARPHRD_NONE) ||
	    ovs_is_internal_dev(vport->dev)) {
		err = -EINVAL;
		goto error_put;
	}

#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
	/* Create symlink from /sys/class/net/<devname>/master to
	 * /sys/class/net/<bridgename>. */
	if (!ovs_is_internal_dev(vport->dev)) {
		if (bridgeName != NULL && *bridgeName)
		{
			bridge = get_vport_by_bridge(vport->dp, bridgeName);
			if (bridge == NULL) {
				err = -EINVAL;
				goto error_put;
			}
		}
	}
#endif

	rtnl_lock();

#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
	vport->dev->priv_flags |= IFF_OVS_DATAPATH;
#else
	err = netdev_master_upper_dev_link(vport->dev,
					   get_dpdev(vport->dp),
					   NULL, NULL, NULL);
	if (err)
		goto error_unlock;
#endif

	err = netdev_rx_handler_register(vport->dev, netdev_frame_hook,
					 vport);
	if (err)
#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
		goto error_unlock;
#else
		goto error_master_upper_dev_unlink;
#endif
#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
	err = netdev_master_upper_dev_link(vport->dev,
					bridge ? bridge->dev : get_dpdev(vport->dp),
					NULL, NULL, NULL);
	if (err)
		goto error_rx_handler_unregister;
#endif

	dev_disable_lro(vport->dev);
	dev_set_promiscuity(vport->dev, 1);
#ifndef CONFIG_OPENVSWITCH_BRCOMPAT
	vport->dev->priv_flags |= IFF_OVS_DATAPATH;
#endif
	rtnl_unlock();

	return vport;

#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
error_rx_handler_unregister:
	netdev_rx_handler_unregister(vport->dev);
#else
error_master_upper_dev_unlink:
	netdev_upper_dev_unlink(vport->dev, get_dpdev(vport->dp));
#endif
error_unlock:
	rtnl_unlock();
error_put:
	dev_put(vport->dev);
error_free_vport:
	ovs_vport_free(vport);
	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(ovs_netdev_link);

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

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

#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
	return ovs_netdev_link(vport, parms->name, parms->bridge_name);
#else
	return ovs_netdev_link(vport, parms->name);
#endif
}

static void vport_netdev_free(struct rcu_head *rcu)
{
	struct vport *vport = container_of(rcu, struct vport, rcu);

	if (vport->dev)
		dev_put(vport->dev);
	ovs_vport_free(vport);
}

#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
static int ovs_brcompat_port_destroy(struct vport *vport)
{
	if (ovs_dp_br_bridge_port_setup) {
		return ovs_dp_br_bridge_port_setup(NULL, vport, 0);
	}

	return EOPNOTSUPP;
}
#endif

void ovs_netdev_detach_dev(struct vport *vport)
{
	ASSERT_RTNL();
#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
	ovs_brcompat_port_destroy(vport);
#endif
	vport->dev->priv_flags &= ~IFF_OVS_DATAPATH;
	netdev_rx_handler_unregister(vport->dev);
	netdev_upper_dev_unlink(vport->dev,
				netdev_master_upper_dev_get(vport->dev));
	dev_set_promiscuity(vport->dev, -1);
}

static void netdev_destroy(struct vport *vport)
{
	rtnl_lock();
	if (netif_is_ovs_port(vport->dev))
		ovs_netdev_detach_dev(vport);
	rtnl_unlock();

#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
	OVS_LOG_DBG("vport %s successfully destroyed \n", vport->dev->name);
#endif
	call_rcu(&vport->rcu, vport_netdev_free);
}

#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
int ovs_netdev_set_addr(struct vport *vport, const unsigned char *addr)
{
	struct sockaddr sa;

	sa.sa_family = ARPHRD_ETHER;
	memcpy(sa.sa_data, addr, ETH_ALEN);

	return dev_set_mac_address(vport->dev, &sa, NULL);
}

const char *ovs_netdev_get_name(const struct vport *vport)
{
	return vport->dev->name;
}

const unsigned char *ovs_netdev_get_addr(const struct vport *vport)
{
	return vport->dev->dev_addr;
}

struct kobject *ovs_netdev_get_kobj(const struct vport *vport)
{
	return &vport->dev->dev.kobj;
}

unsigned ovs_netdev_get_dev_flags(const struct vport *vport)
{
	return dev_get_flags(vport->dev);
}

int ovs_netdev_is_running(const struct vport *vport)
{
	return netif_running(vport->dev);
}

unsigned char ovs_netdev_get_operstate(const struct vport *vport)
{
	return vport->dev->operstate;
}

int ovs_netdev_get_ifindex(const struct vport *vport)
{
	return vport->dev->ifindex;
}

int ovs_netdev_get_mtu(const struct vport *vport)
{
	return vport->dev->mtu;
}
#endif /* CONFIG_OPENVSWITCH_BRCOMPAT */

void ovs_netdev_tunnel_destroy(struct vport *vport)
{
	rtnl_lock();
	if (netif_is_ovs_port(vport->dev))
		ovs_netdev_detach_dev(vport);

	/* We can be invoked by both explicit vport deletion and
	 * underlying netdev deregistration; delete the link only
	 * if it's not already shutting down.
	 */
	if (vport->dev->reg_state == NETREG_REGISTERED)
		rtnl_delete_link(vport->dev);
	dev_put(vport->dev);
	vport->dev = NULL;
	rtnl_unlock();

	call_rcu(&vport->rcu, vport_netdev_free);
}
EXPORT_SYMBOL_GPL(ovs_netdev_tunnel_destroy);

/* Returns null if this device is not attached to a datapath. */
struct vport *ovs_netdev_get_vport(struct net_device *dev)
{
	if (likely(netif_is_ovs_port(dev)))
		return (struct vport *)
			rcu_dereference_rtnl(dev->rx_handler_data);
	else
		return NULL;
}
#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
EXPORT_SYMBOL(ovs_netdev_get_vport);
#endif

static struct vport_ops ovs_netdev_vport_ops = {
	.type		= OVS_VPORT_TYPE_NETDEV,
	.create		= netdev_create,
	.destroy	= netdev_destroy,
#ifdef CONFIG_OPENVSWITCH_BRCOMPAT
	.set_addr	= ovs_netdev_set_addr,
	.get_name	= ovs_netdev_get_name,
	.get_addr	= ovs_netdev_get_addr,
	.get_kobj	= ovs_netdev_get_kobj,
	.get_dev_flags	= ovs_netdev_get_dev_flags,
	.is_running	= ovs_netdev_is_running,
	.get_operstate	= ovs_netdev_get_operstate,
	.get_ifindex	= ovs_netdev_get_ifindex,
	.get_mtu	= ovs_netdev_get_mtu,
#endif
	.send		= dev_queue_xmit,
};

int __init ovs_netdev_init(void)
{
	return ovs_vport_ops_register(&ovs_netdev_vport_ops);
}

void ovs_netdev_exit(void)
{
	ovs_vport_ops_unregister(&ovs_netdev_vport_ops);
}