#include <linux/kernel.h>
  #include <linux/netdevice.h>
  #include <linux/rtnetlink.h>
  #include <linux/slab.h>
  
  #include "br_private.h"
  
  static void __vlan_add_pvid(struct net_port_vlans *v, u16 vid)
  {
  	if (v->pvid == vid)
  		return;
  
  	smp_wmb();
  	v->pvid = vid;
  }
  
  static void __vlan_delete_pvid(struct net_port_vlans *v, u16 vid)
  {
  	if (v->pvid != vid)
  		return;
  
  	smp_wmb();
  	v->pvid = 0;
  }
  
  static void __vlan_add_flags(struct net_port_vlans *v, u16 vid, u16 flags)
  {
  	if (flags & BRIDGE_VLAN_INFO_PVID)
  		__vlan_add_pvid(v, vid);
  
  	if (flags & BRIDGE_VLAN_INFO_UNTAGGED)
  		set_bit(vid, v->untagged_bitmap);
  }
  
  static int __vlan_add(struct net_port_vlans *v, u16 vid, u16 flags)
  {
  	struct net_bridge_port *p = NULL;
  	struct net_bridge *br;
  	struct net_device *dev;
  	int err;
  
  	if (test_bit(vid, v->vlan_bitmap)) {
  		__vlan_add_flags(v, vid, flags);
  		return 0;
  	}
  
  	if (v->port_idx) {
  		p = v->parent.port;
  		br = p->br;
  		dev = p->dev;
  	} else {
  		br = v->parent.br;
  		dev = br->dev;
  	}
  
  	if (p) {
  		/* Add VLAN to the device filter if it is supported.
  		 * Stricly speaking, this is not necessary now, since
  		 * devices are made promiscuous by the bridge, but if
  		 * that ever changes this code will allow tagged
  		 * traffic to enter the bridge.
  		 */
  		err = vlan_vid_add(dev, htons(ETH_P_8021Q), vid);
  		if (err)
  			return err;
  	}
  
  	err = br_fdb_insert(br, p, dev->dev_addr, vid);
  	if (err) {
  		br_err(br, "failed insert local address into bridge "
  		       "forwarding table
  ");
  		goto out_filt;
  	}
  
  	set_bit(vid, v->vlan_bitmap);
  	v->num_vlans++;
  	__vlan_add_flags(v, vid, flags);
  
  	return 0;
  
  out_filt:
  	if (p)
  		vlan_vid_del(dev, htons(ETH_P_8021Q), vid);
  	return err;
  }
  
  static int __vlan_del(struct net_port_vlans *v, u16 vid)
  {
  	if (!test_bit(vid, v->vlan_bitmap))
  		return -EINVAL;
  
  	__vlan_delete_pvid(v, vid);
  	clear_bit(vid, v->untagged_bitmap);
  
  	if (v->port_idx)
  		vlan_vid_del(v->parent.port->dev, htons(ETH_P_8021Q), vid);
  
  	clear_bit(vid, v->vlan_bitmap);
  	v->num_vlans--;
  	if (bitmap_empty(v->vlan_bitmap, VLAN_N_VID)) {
  		if (v->port_idx)
  			rcu_assign_pointer(v->parent.port->vlan_info, NULL);
  		else
  			rcu_assign_pointer(v->parent.br->vlan_info, NULL);
  		kfree_rcu(v, rcu);
  	}
  	return 0;
  }
  
  static void __vlan_flush(struct net_port_vlans *v)
  {
  	smp_wmb();
  	v->pvid = 0;
  	bitmap_zero(v->vlan_bitmap, VLAN_N_VID);
  	if (v->port_idx)
  		rcu_assign_pointer(v->parent.port->vlan_info, NULL);
  	else
  		rcu_assign_pointer(v->parent.br->vlan_info, NULL);
  	kfree_rcu(v, rcu);
  }
  
  struct sk_buff *br_handle_vlan(struct net_bridge *br,
  			       const struct net_port_vlans *pv,
  			       struct sk_buff *skb)
  {
  	u16 vid;
  
  	/* If this packet was not filtered at input, let it pass */
  	if (!BR_INPUT_SKB_CB(skb)->vlan_filtered)
  		goto out;
  
  	/* Vlan filter table must be configured at this point.  The
  	 * only exception is the bridge is set in promisc mode and the
  	 * packet is destined for the bridge device.  In this case
  	 * pass the packet as is.
  	 */
  	if (!pv) {
  		if ((br->dev->flags & IFF_PROMISC) && skb->dev == br->dev) {
  			goto out;
  		} else {
  			kfree_skb(skb);
  			return NULL;
  		}
  	}
  
  	/* At this point, we know that the frame was filtered and contains
  	 * a valid vlan id.  If the vlan id is set in the untagged bitmap,
  	 * send untagged; otherwise, send tagged.
  	 */
  	br_vlan_get_tag(skb, &vid);
  	if (test_bit(vid, pv->untagged_bitmap))
  		skb->vlan_tci = 0;
  
  out:
  	return skb;
  }
  
  /* Called under RCU */
  bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
  			struct sk_buff *skb, u16 *vid)
  {
  	int err;
  
  	/* If VLAN filtering is disabled on the bridge, all packets are
  	 * permitted.
  	 */
  	if (!br->vlan_enabled) {
  		BR_INPUT_SKB_CB(skb)->vlan_filtered = false;
  		return true;
  	}
  
  	/* If there are no vlan in the permitted list, all packets are
  	 * rejected.
  	 */
  	if (!v)
  		goto drop;
  
  	BR_INPUT_SKB_CB(skb)->vlan_filtered = true;
  
  	/* If vlan tx offload is disabled on bridge device and frame was
  	 * sent from vlan device on the bridge device, it does not have
  	 * HW accelerated vlan tag.
  	 */
  	if (unlikely(!vlan_tx_tag_present(skb) &&
  		     (skb->protocol == htons(ETH_P_8021Q) ||
  		      skb->protocol == htons(ETH_P_8021AD)))) {
  		skb = skb_vlan_untag(skb);
  		if (unlikely(!skb))
  			return false;
  	}
  
  	err = br_vlan_get_tag(skb, vid);
  	if (!*vid) {
  		u16 pvid = br_get_pvid(v);
  
  		/* Frame had a tag with VID 0 or did not have a tag.
  		 * See if pvid is set on this port.  That tells us which
  		 * vlan untagged or priority-tagged traffic belongs to.
  		 */
  		if (pvid == VLAN_N_VID)
  			goto drop;
  
  		/* PVID is set on this port.  Any untagged or priority-tagged
  		 * ingress frame is considered to belong to this vlan.
  		 */
  		*vid = pvid;
  		if (likely(err))
  			/* Untagged Frame. */
  			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), pvid);
  		else
  			/* Priority-tagged Frame.
  			 * At this point, We know that skb->vlan_tci had
  			 * VLAN_TAG_PRESENT bit and its VID field was 0x000.
  			 * We update only VID field and preserve PCP field.
  			 */
  			skb->vlan_tci |= pvid;
  
  		return true;
  	}
  
  	/* Frame had a valid vlan tag.  See if vlan is allowed */
  	if (test_bit(*vid, v->vlan_bitmap))
  		return true;
  drop:
  	kfree_skb(skb);
  	return false;
  }
  
  /* Called under RCU. */
  bool br_allowed_egress(struct net_bridge *br,
  		       const struct net_port_vlans *v,
  		       const struct sk_buff *skb)
  {
  	u16 vid;
  
  	/* If this packet was not filtered at input, let it pass */
  	if (!BR_INPUT_SKB_CB(skb)->vlan_filtered)
  		return true;
  
  	if (!v)
  		return false;
  
  	br_vlan_get_tag(skb, &vid);
  	if (test_bit(vid, v->vlan_bitmap))
  		return true;
  
  	return false;
  }
  
  /* Called under RCU */
  bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid)
  {
  	struct net_bridge *br = p->br;
  	struct net_port_vlans *v;
  
  	/* If filtering was disabled at input, let it pass. */
  	if (!br->vlan_enabled)
  		return true;
  
  	v = rcu_dereference(p->vlan_info);
  	if (!v)
  		return false;
  
  	br_vlan_get_tag(skb, vid);
  	if (!*vid) {
  		*vid = br_get_pvid(v);
  		if (*vid == VLAN_N_VID)
  			return false;
  
  		return true;
  	}
  
  	if (test_bit(*vid, v->vlan_bitmap))
  		return true;
  
  	return false;
  }
  
  /* Must be protected by RTNL.
   * Must be called with vid in range from 1 to 4094 inclusive.
   */
  int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
  {
  	struct net_port_vlans *pv = NULL;
  	int err;
  
  	ASSERT_RTNL();
  
  	pv = rtnl_dereference(br->vlan_info);
  	if (pv)
  		return __vlan_add(pv, vid, flags);
  
  	/* Create port vlan infomration
  	 */
  	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
  	if (!pv)
  		return -ENOMEM;
  
  	pv->parent.br = br;
  	err = __vlan_add(pv, vid, flags);
  	if (err)
  		goto out;
  
  	rcu_assign_pointer(br->vlan_info, pv);
  	return 0;
  out:
  	kfree(pv);
  	return err;
  }
  
  /* Must be protected by RTNL.
   * Must be called with vid in range from 1 to 4094 inclusive.
   */
  int br_vlan_delete(struct net_bridge *br, u16 vid)
  {
  	struct net_port_vlans *pv;
  
  	ASSERT_RTNL();
  
  	pv = rtnl_dereference(br->vlan_info);
  	if (!pv)
  		return -EINVAL;
  
  	br_fdb_find_delete_local(br, NULL, br->dev->dev_addr, vid);
  
  	__vlan_del(pv, vid);
  	return 0;
  }
  
  void br_vlan_flush(struct net_bridge *br)
  {
  	struct net_port_vlans *pv;
  
  	ASSERT_RTNL();
  	pv = rtnl_dereference(br->vlan_info);
  	if (!pv)
  		return;
  
  	__vlan_flush(pv);
  }
  
  bool br_vlan_find(struct net_bridge *br, u16 vid)
  {
  	struct net_port_vlans *pv;
  	bool found = false;
  
  	rcu_read_lock();
  	pv = rcu_dereference(br->vlan_info);
  
  	if (!pv)
  		goto out;
  
  	if (test_bit(vid, pv->vlan_bitmap))
  		found = true;
  
  out:
  	rcu_read_unlock();
  	return found;
  }
  
  int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
  {
  	if (!rtnl_trylock())
  		return restart_syscall();
  
  	if (br->vlan_enabled == val)
  		goto unlock;
  
  	br->vlan_enabled = val;
  
  unlock:
  	rtnl_unlock();
  	return 0;
  }
  
  /* Must be protected by RTNL.
   * Must be called with vid in range from 1 to 4094 inclusive.
   */
  int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
  {
  	struct net_port_vlans *pv = NULL;
  	int err;
  
  	ASSERT_RTNL();
  
  	pv = rtnl_dereference(port->vlan_info);
  	if (pv)
  		return __vlan_add(pv, vid, flags);
  
  	/* Create port vlan infomration
  	 */
  	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
  	if (!pv) {
  		err = -ENOMEM;
  		goto clean_up;
  	}
  
  	pv->port_idx = port->port_no;
  	pv->parent.port = port;
  	err = __vlan_add(pv, vid, flags);
  	if (err)
  		goto clean_up;
  
  	rcu_assign_pointer(port->vlan_info, pv);
  	return 0;
  
  clean_up:
  	kfree(pv);
  	return err;
  }
  
  /* Must be protected by RTNL.
   * Must be called with vid in range from 1 to 4094 inclusive.
   */
  int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
  {
  	struct net_port_vlans *pv;
  
  	ASSERT_RTNL();
  
  	pv = rtnl_dereference(port->vlan_info);
  	if (!pv)
  		return -EINVAL;
  
  	br_fdb_find_delete_local(port->br, port, port->dev->dev_addr, vid);
  
  	return __vlan_del(pv, vid);
  }
  
  void nbp_vlan_flush(struct net_bridge_port *port)
  {
  	struct net_port_vlans *pv;
  	u16 vid;
  
  	ASSERT_RTNL();
  
  	pv = rtnl_dereference(port->vlan_info);
  	if (!pv)
  		return;
  
  	for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
  		vlan_vid_del(port->dev, htons(ETH_P_8021Q), vid);
  
  	__vlan_flush(pv);
  }
  
  bool nbp_vlan_find(struct net_bridge_port *port, u16 vid)
  {
  	struct net_port_vlans *pv;
  	bool found = false;
  
  	rcu_read_lock();
  	pv = rcu_dereference(port->vlan_info);
  
  	if (!pv)
  		goto out;
  
  	if (test_bit(vid, pv->vlan_bitmap))
  		found = true;
  
  out:
  	rcu_read_unlock();
  	return found;
  }