// SPDX-License-Identifier: GPL-2.0

  #include <linux/skbuff.h>
  #include <linux/netdevice.h>
  #include <linux/if_vlan.h>

  #include <linux/netpoll.h>

  #include <linux/export.h>

  #include "vlan.h"

  bool vlan_do_receive(struct sk_buff **skbp)

  {

  	struct sk_buff *skb = *skbp;

  	__be16 vlan_proto = skb->vlan_proto;

  	u16 vlan_id = skb_vlan_tag_get_id(skb);

  	struct net_device *vlan_dev;

  	struct vlan_pcpu_stats *rx_stats;

  	vlan_dev = vlan_find_dev(skb->dev, vlan_proto, vlan_id);

  	if (!vlan_dev)

  		return false;

  	skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
  	if (unlikely(!skb))
  		return false;

  
  	if (unlikely(!(vlan_dev->flags & IFF_UP))) {
  		kfree_skb(skb);
  		*skbp = NULL;
  		return false;
  	}

  	skb->dev = vlan_dev;

  	if (unlikely(skb->pkt_type == PACKET_OTHERHOST)) {

  		/* Our lower layer thinks this is not local, let's make sure.
  		 * This allows the VLAN to have a different MAC than the
  		 * underlying device, and still route correctly. */

  		if (ether_addr_equal_64bits(eth_hdr(skb)->h_dest, vlan_dev->dev_addr))

  			skb->pkt_type = PACKET_HOST;
  	}

  	if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR) &&
  	    !netif_is_macvlan_port(vlan_dev) &&
  	    !netif_is_bridge_port(vlan_dev)) {

  		unsigned int offset = skb->data - skb_mac_header(skb);
  
  		/*
  		 * vlan_insert_tag expect skb->data pointing to mac header.
  		 * So change skb->data before calling it and change back to
  		 * original position later
  		 */
  		skb_push(skb, offset);

  		skb = *skbp = vlan_insert_inner_tag(skb, skb->vlan_proto,
  						    skb->vlan_tci, skb->mac_len);

  		if (!skb)
  			return false;
  		skb_pull(skb, offset + VLAN_HLEN);
  		skb_reset_mac_len(skb);
  	}

  	skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);

  	skb->vlan_tci = 0;

  	rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);

  	u64_stats_update_begin(&rx_stats->syncp);

  	rx_stats->rx_packets++;
  	rx_stats->rx_bytes += skb->len;

  	if (skb->pkt_type == PACKET_MULTICAST)

  		rx_stats->rx_multicast++;

  	u64_stats_update_end(&rx_stats->syncp);

  
  	return true;

  }

  /* Must be invoked with rcu_read_lock. */

  struct net_device *__vlan_find_dev_deep_rcu(struct net_device *dev,

  					__be16 vlan_proto, u16 vlan_id)

  {

  	struct vlan_info *vlan_info = rcu_dereference(dev->vlan_info);

  	if (vlan_info) {

  		return vlan_group_get_device(&vlan_info->grp,
  					     vlan_proto, vlan_id);

  	} else {
  		/*

  		 * Lower devices of master uppers (bonding, team) do not have
  		 * grp assigned to themselves. Grp is assigned to upper device
  		 * instead.

  		 */

  		struct net_device *upper_dev;
  
  		upper_dev = netdev_master_upper_dev_get_rcu(dev);
  		if (upper_dev)

  			return __vlan_find_dev_deep_rcu(upper_dev,

  						    vlan_proto, vlan_id);

  	}
  
  	return NULL;
  }

  EXPORT_SYMBOL(__vlan_find_dev_deep_rcu);

  struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  {

  	struct net_device *ret = vlan_dev_priv(dev)->real_dev;
  
  	while (is_vlan_dev(ret))
  		ret = vlan_dev_priv(ret)->real_dev;
  
  	return ret;

  }

  EXPORT_SYMBOL(vlan_dev_real_dev);

  
  u16 vlan_dev_vlan_id(const struct net_device *dev)
  {

  	return vlan_dev_priv(dev)->vlan_id;

  }

  EXPORT_SYMBOL(vlan_dev_vlan_id);

  __be16 vlan_dev_vlan_proto(const struct net_device *dev)
  {
  	return vlan_dev_priv(dev)->vlan_proto;
  }
  EXPORT_SYMBOL(vlan_dev_vlan_proto);

  /*
   * vlan info and vid list
   */
  
  static void vlan_group_free(struct vlan_group *grp)
  {

  	int i, j;

  	for (i = 0; i < VLAN_PROTO_NUM; i++)
  		for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
  			kfree(grp->vlan_devices_arrays[i][j]);

  }
  
  static void vlan_info_free(struct vlan_info *vlan_info)
  {
  	vlan_group_free(&vlan_info->grp);
  	kfree(vlan_info);
  }
  
  static void vlan_info_rcu_free(struct rcu_head *rcu)
  {
  	vlan_info_free(container_of(rcu, struct vlan_info, rcu));
  }
  
  static struct vlan_info *vlan_info_alloc(struct net_device *dev)
  {
  	struct vlan_info *vlan_info;
  
  	vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
  	if (!vlan_info)
  		return NULL;
  
  	vlan_info->real_dev = dev;
  	INIT_LIST_HEAD(&vlan_info->vid_list);
  	return vlan_info;
  }
  
  struct vlan_vid_info {
  	struct list_head list;

  	__be16 proto;
  	u16 vid;

  	int refcount;
  };

  static bool vlan_hw_filter_capable(const struct net_device *dev,
  				     const struct vlan_vid_info *vid_info)
  {
  	if (vid_info->proto == htons(ETH_P_8021Q) &&
  	    dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
  		return true;
  	if (vid_info->proto == htons(ETH_P_8021AD) &&
  	    dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
  		return true;
  	return false;
  }

  static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,

  					       __be16 proto, u16 vid)

  {
  	struct vlan_vid_info *vid_info;
  
  	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {

  		if (vid_info->proto == proto && vid_info->vid == vid)

  			return vid_info;
  	}
  	return NULL;
  }

  static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)

  {
  	struct vlan_vid_info *vid_info;
  
  	vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
  	if (!vid_info)
  		return NULL;

  	vid_info->proto = proto;

  	vid_info->vid = vid;
  
  	return vid_info;
  }

  static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,

  			  struct vlan_vid_info **pvid_info)

  {

  	struct net_device *dev = vlan_info->real_dev;

  	const struct net_device_ops *ops = dev->netdev_ops;

  	struct vlan_vid_info *vid_info;
  	int err;

  	vid_info = vlan_vid_info_alloc(proto, vid);

  	if (!vid_info)
  		return -ENOMEM;

  	if (vlan_hw_filter_capable(dev, vid_info)) {

  		if (netif_device_present(dev))
  			err = ops->ndo_vlan_rx_add_vid(dev, proto, vid);
  		else
  			err = -ENODEV;

  		if (err) {
  			kfree(vid_info);
  			return err;
  		}

  	}

  	list_add(&vid_info->list, &vlan_info->vid_list);
  	vlan_info->nr_vids++;
  	*pvid_info = vid_info;

  	return 0;
  }

  int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)

  {
  	struct vlan_info *vlan_info;
  	struct vlan_vid_info *vid_info;
  	bool vlan_info_created = false;
  	int err;
  
  	ASSERT_RTNL();
  
  	vlan_info = rtnl_dereference(dev->vlan_info);
  	if (!vlan_info) {
  		vlan_info = vlan_info_alloc(dev);
  		if (!vlan_info)
  			return -ENOMEM;
  		vlan_info_created = true;
  	}

  	vid_info = vlan_vid_info_get(vlan_info, proto, vid);

  	if (!vid_info) {

  		err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);

  		if (err)
  			goto out_free_vlan_info;
  	}
  	vid_info->refcount++;
  
  	if (vlan_info_created)
  		rcu_assign_pointer(dev->vlan_info, vlan_info);
  
  	return 0;
  
  out_free_vlan_info:
  	if (vlan_info_created)
  		kfree(vlan_info);
  	return err;
  }

  EXPORT_SYMBOL(vlan_vid_add);

  static void __vlan_vid_del(struct vlan_info *vlan_info,
  			   struct vlan_vid_info *vid_info)

  {

  	struct net_device *dev = vlan_info->real_dev;

  	const struct net_device_ops *ops = dev->netdev_ops;

  	__be16 proto = vid_info->proto;
  	u16 vid = vid_info->vid;

  	int err;

  	if (vlan_hw_filter_capable(dev, vid_info)) {

  		if (netif_device_present(dev))
  			err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
  		else
  			err = -ENODEV;

  		if (err) {

  			pr_warn("failed to kill vid %04x/%d for device %s
  ",
  				proto, vid, dev->name);

  		}
  	}
  	list_del(&vid_info->list);
  	kfree(vid_info);
  	vlan_info->nr_vids--;
  }

  void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)

  {
  	struct vlan_info *vlan_info;
  	struct vlan_vid_info *vid_info;
  
  	ASSERT_RTNL();
  
  	vlan_info = rtnl_dereference(dev->vlan_info);
  	if (!vlan_info)
  		return;

  	vid_info = vlan_vid_info_get(vlan_info, proto, vid);

  	if (!vid_info)
  		return;
  	vid_info->refcount--;
  	if (vid_info->refcount == 0) {
  		__vlan_vid_del(vlan_info, vid_info);
  		if (vlan_info->nr_vids == 0) {
  			RCU_INIT_POINTER(dev->vlan_info, NULL);
  			call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
  		}

  	}
  }
  EXPORT_SYMBOL(vlan_vid_del);

  
  int vlan_vids_add_by_dev(struct net_device *dev,
  			 const struct net_device *by_dev)
  {
  	struct vlan_vid_info *vid_info;

  	struct vlan_info *vlan_info;

  	int err;
  
  	ASSERT_RTNL();

  	vlan_info = rtnl_dereference(by_dev->vlan_info);
  	if (!vlan_info)

  		return 0;

  	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {

  		err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);

  		if (err)
  			goto unwind;
  	}
  	return 0;
  
  unwind:
  	list_for_each_entry_continue_reverse(vid_info,

  					     &vlan_info->vid_list,

  					     list) {

  		vlan_vid_del(dev, vid_info->proto, vid_info->vid);

  	}
  
  	return err;
  }
  EXPORT_SYMBOL(vlan_vids_add_by_dev);
  
  void vlan_vids_del_by_dev(struct net_device *dev,
  			  const struct net_device *by_dev)
  {
  	struct vlan_vid_info *vid_info;

  	struct vlan_info *vlan_info;

  
  	ASSERT_RTNL();

  	vlan_info = rtnl_dereference(by_dev->vlan_info);
  	if (!vlan_info)

  		return;

  	list_for_each_entry(vid_info, &vlan_info->vid_list, list)

  		vlan_vid_del(dev, vid_info->proto, vid_info->vid);

  }
  EXPORT_SYMBOL(vlan_vids_del_by_dev);

  
  bool vlan_uses_dev(const struct net_device *dev)
  {

  	struct vlan_info *vlan_info;
  
  	ASSERT_RTNL();
  
  	vlan_info = rtnl_dereference(dev->vlan_info);
  	if (!vlan_info)
  		return false;
  	return vlan_info->grp.nr_vlan_devs ? true : false;

  }
  EXPORT_SYMBOL(vlan_uses_dev);