Commit 250ba748 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'macvlan-less-mcast-cloning' 



Herbert Xu says:

====================
macvlan: Avoid unnecessary multicast cloning

This patch tries to improve macvlan multicast performance by
maintaining a filter hash at the macvlan_port level so that we
can quickly determine whether a given packet is needed or not.

It is preceded by a patch that fixes a potential use-after-free
bug that I discovered while looking over this.

v2 fixed a bug where promiscuous/allmulti settings weren't handled
correctly.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 595d0b29 9c127a01

drivers/net/macvlan.c

+41 −7
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ struct macvlan_port { 
	bool 			passthru;

	int			count;

	struct hlist_head	vlan_source_hash[MACVLAN_HASH_SIZE];

	DECLARE_BITMAP(mc_filter, MACVLAN_MC_FILTER_SZ);

};



struct macvlan_source_entry {
@@ -305,11 +306,14 @@ static void macvlan_process_broadcast(struct work_struct *w) 


		rcu_read_unlock();



		if (src)

			dev_put(src->dev);

		kfree_skb(skb);

	}

}



static void macvlan_broadcast_enqueue(struct macvlan_port *port,

				      const struct macvlan_dev *src,

				      struct sk_buff *skb)

{

	struct sk_buff *nskb;
@@ -319,8 +323,12 @@ static void macvlan_broadcast_enqueue(struct macvlan_port *port, 
	if (!nskb)

		goto err;



	MACVLAN_SKB_CB(nskb)->src = src;



	spin_lock(&port->bc_queue.lock);

	if (skb_queue_len(&port->bc_queue) < MACVLAN_BC_QUEUE_LEN) {

		if (src)

			dev_hold(src->dev);

		__skb_queue_tail(&port->bc_queue, nskb);

		err = 0;

	}
@@ -412,6 +420,8 @@ static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb) 


	port = macvlan_port_get_rcu(skb->dev);

	if (is_multicast_ether_addr(eth->h_dest)) {

		unsigned int hash;



		skb = ip_check_defrag(dev_net(skb->dev), skb, IP_DEFRAG_MACVLAN);

		if (!skb)

			return RX_HANDLER_CONSUMED;
@@ -429,8 +439,9 @@ static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb) 
			goto out;

		}



		MACVLAN_SKB_CB(skb)->src = src;

		macvlan_broadcast_enqueue(port, skb);

		hash = mc_hash(NULL, eth->h_dest);

		if (test_bit(hash, port->mc_filter))

			macvlan_broadcast_enqueue(port, src, skb);



		return RX_HANDLER_PASS;

	}
@@ -716,12 +727,12 @@ static void macvlan_change_rx_flags(struct net_device *dev, int change) 
	}

}



static void macvlan_set_mac_lists(struct net_device *dev)

static void macvlan_compute_filter(unsigned long *mc_filter,

				   struct net_device *dev,

				   struct macvlan_dev *vlan)

{

	struct macvlan_dev *vlan = netdev_priv(dev);



	if (dev->flags & (IFF_PROMISC | IFF_ALLMULTI)) {

		bitmap_fill(vlan->mc_filter, MACVLAN_MC_FILTER_SZ);

		bitmap_fill(mc_filter, MACVLAN_MC_FILTER_SZ);

	} else {

		struct netdev_hw_addr *ha;

		DECLARE_BITMAP(filter, MACVLAN_MC_FILTER_SZ);
@@ -733,10 +744,33 @@ static void macvlan_set_mac_lists(struct net_device *dev) 


		__set_bit(mc_hash(vlan, dev->broadcast), filter);



		bitmap_copy(vlan->mc_filter, filter, MACVLAN_MC_FILTER_SZ);

		bitmap_copy(mc_filter, filter, MACVLAN_MC_FILTER_SZ);

	}

}



static void macvlan_set_mac_lists(struct net_device *dev)

{

	struct macvlan_dev *vlan = netdev_priv(dev);



	macvlan_compute_filter(vlan->mc_filter, dev, vlan);



	dev_uc_sync(vlan->lowerdev, dev);

	dev_mc_sync(vlan->lowerdev, dev);



	/* This is slightly inaccurate as we're including the subscription

	 * list of vlan->lowerdev too.

	 *

	 * Bug alert: This only works if everyone has the same broadcast

	 * address as lowerdev.  As soon as someone changes theirs this

	 * will break.

	 *

	 * However, this is already broken as when you change your broadcast

	 * address we don't get called.

	 *

	 * The solution is to maintain a list of broadcast addresses like

	 * we do for uc/mc, if you care.

	 */

	macvlan_compute_filter(vlan->port->mc_filter, vlan->lowerdev, NULL);

}



static int macvlan_change_mtu(struct net_device *dev, int new_mtu)

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