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

  /*

   * Copyright (c) 2007-2012 Nicira, 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(skb, ETH_HLEN);
  		skb_postpush_rcsum(skb, skb->data, 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);

  	return local->dev;

  }

  struct vport *ovs_netdev_link(struct vport *vport, const char *name)

  {

  	int err;

  	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;
  	}

  	rtnl_lock();

  	err = netdev_master_upper_dev_link(vport->dev,

  					   get_dpdev(vport->dp),
  					   NULL, NULL, NULL);

  	if (err)
  		goto error_unlock;

  	err = netdev_rx_handler_register(vport->dev, netdev_frame_hook,

  					 vport);
  	if (err)

  		goto error_master_upper_dev_unlink;

  	dev_disable_lro(vport->dev);
  	dev_set_promiscuity(vport->dev, 1);
  	vport->dev->priv_flags |= IFF_OVS_DATAPATH;

  	rtnl_unlock();

  
  	return vport;

  error_master_upper_dev_unlink:

  	netdev_upper_dev_unlink(vport->dev, get_dpdev(vport->dp));

  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;

  	return ovs_netdev_link(vport, parms->name);

  }

  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);

  }

  void ovs_netdev_detach_dev(struct vport *vport)

  {

  	ASSERT_RTNL();

  	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();

  	call_rcu(&vport->rcu, vport_netdev_free);

  }

  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;
  }

  static struct vport_ops ovs_netdev_vport_ops = {

  	.type		= OVS_VPORT_TYPE_NETDEV,
  	.create		= netdev_create,
  	.destroy	= netdev_destroy,

  	.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);
  }