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: Eric Dumazet <edumazet@google.com>
Cc: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2013-02-05 20:22:50 +00:00 committed by David S. Miller
parent 6d1ccff627
commit cd431e7385
2 changed files with 29 additions and 0 deletions

View file

@ -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);
}

View file

@ -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);