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Commit cd431e73 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

macvlan: add multicast filter 



Setting up IPv6 addresses on configurations with many macvlans
is not really working, as many multicast messages are dropped.

Add a multicast filter to macvlan to reduce the amount of cloned
skbs and overhead.

Successfully tested with 1024 macvlans on one ethernet device.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Ben Greear <greearb@candelatech.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6d1ccff6

drivers/net/macvlan.c

+23 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include <linux/if_vlan.h>

#include <linux/if_link.h>

#include <linux/if_macvlan.h>

#include <linux/hash.h>

#include <net/rtnetlink.h>

#include <net/xfrm.h>
@@ -126,6 +127,13 @@ static int macvlan_broadcast_one(struct sk_buff *skb, 
	return vlan->receive(skb);

}



static unsigned int mc_hash(const unsigned char *addr)

{

	u32 val = __get_unaligned_cpu32(addr + 2);



	return hash_32(val, MACVLAN_MC_FILTER_BITS);

}



static void macvlan_broadcast(struct sk_buff *skb,

			      const struct macvlan_port *port,

			      struct net_device *src,
@@ -137,6 +145,7 @@ static void macvlan_broadcast(struct sk_buff *skb, 
	struct sk_buff *nskb;

	unsigned int i;

	int err;

	unsigned int hash = mc_hash(eth->h_dest);



	if (skb->protocol == htons(ETH_P_PAUSE))

		return;
@@ -146,6 +155,8 @@ static void macvlan_broadcast(struct sk_buff *skb, 
			if (vlan->dev == src || !(vlan->mode & mode))

				continue;



			if (!test_bit(hash, vlan->mc_filter))

				continue;

			nskb = skb_clone(skb, GFP_ATOMIC);

			err = macvlan_broadcast_one(nskb, vlan, eth,

					 mode == MACVLAN_MODE_BRIDGE);
@@ -405,6 +416,18 @@ static void macvlan_set_mac_lists(struct net_device *dev) 
{

	struct macvlan_dev *vlan = netdev_priv(dev);



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

		bitmap_fill(vlan->mc_filter, MACVLAN_MC_FILTER_SZ);

	} else {

		struct netdev_hw_addr *ha;

		DECLARE_BITMAP(filter, MACVLAN_MC_FILTER_SZ);



		bitmap_zero(filter, MACVLAN_MC_FILTER_SZ);

		netdev_for_each_mc_addr(ha, dev) {

			__set_bit(mc_hash(ha->addr), filter);

		}

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

	}

	dev_uc_sync(vlan->lowerdev, dev);

	dev_mc_sync(vlan->lowerdev, dev);

}

include/linux/if_macvlan.h

+6 −0
Original line number Diff line number Diff line
@@ -52,6 +52,9 @@ struct macvlan_pcpu_stats { 
 */

#define MAX_MACVTAP_QUEUES	(NR_CPUS < 16 ? NR_CPUS : 16)



#define MACVLAN_MC_FILTER_BITS	8

#define MACVLAN_MC_FILTER_SZ	(1 << MACVLAN_MC_FILTER_BITS)



struct macvlan_dev {

	struct net_device	*dev;

	struct list_head	list;
@@ -59,6 +62,9 @@ struct macvlan_dev { 
	struct macvlan_port	*port;

	struct net_device	*lowerdev;

	struct macvlan_pcpu_stats __percpu *pcpu_stats;



	DECLARE_BITMAP(mc_filter, MACVLAN_MC_FILTER_SZ);



	enum macvlan_mode	mode;

	u16			flags;

	int (*receive)(struct sk_buff *skb);