Commit 95ec3eb4 authored by David S. Miller's avatar David S. Miller
Browse files

packet: Add 'cpu' fanout policy. 



Unfortunately we have to use a real modulus here as
the multiply trick won't work as effectively with cpu
numbers as it does with rxhash values.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 81b16ba2

include/linux/if_packet.h

+1 −0
Original line number Diff line number Diff line
@@ -53,6 +53,7 @@ struct sockaddr_ll { 


#define PACKET_FANOUT_HASH		0

#define PACKET_FANOUT_LB		1

#define PACKET_FANOUT_CPU		2

#define PACKET_FANOUT_FLAG_DEFRAG	0x8000



struct tpacket_stats {

net/packet/af_packet.c

+28 −37
Original line number Diff line number Diff line
@@ -447,6 +447,13 @@ static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb 
	return f->arr[cur];

}



static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)

{

	unsigned int cpu = smp_processor_id();



	return f->arr[cpu % num];

}



static struct sk_buff *fanout_check_defrag(struct sk_buff *skb)

{

	const struct iphdr *iph;
@@ -482,7 +489,7 @@ static struct sk_buff *fanout_check_defrag(struct sk_buff *skb) 
	return skb;

}



static int packet_rcv_fanout_hash(struct sk_buff *skb, struct net_device *dev,

static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,

			     struct packet_type *pt, struct net_device *orig_dev)

{

	struct packet_fanout *f = pt->af_packet_priv;
@@ -496,35 +503,25 @@ static int packet_rcv_fanout_hash(struct sk_buff *skb, struct net_device *dev, 
		return 0;

	}



	switch (f->type) {

	case PACKET_FANOUT_HASH:

	default:

		if (f->defrag) {

			skb = fanout_check_defrag(skb);

			if (!skb)

				return 0;

		}



		skb_get_rxhash(skb);



		sk = fanout_demux_hash(f, skb, num);

	po = pkt_sk(sk);



	return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);

}



static int packet_rcv_fanout_lb(struct sk_buff *skb, struct net_device *dev,

				struct packet_type *pt, struct net_device *orig_dev)

{

	struct packet_fanout *f = pt->af_packet_priv;

	unsigned int num = f->num_members;

	struct packet_sock *po;

	struct sock *sk;



	if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||

	    !num) {

		kfree_skb(skb);

		return 0;

		break;

	case PACKET_FANOUT_LB:

		sk = fanout_demux_lb(f, skb, num);

		break;

	case PACKET_FANOUT_CPU:

		sk = fanout_demux_cpu(f, skb, num);

		break;

	}



	sk = fanout_demux_lb(f, skb, num);

	po = pkt_sk(sk);



	return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
@@ -571,6 +568,7 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 
	switch (type) {

	case PACKET_FANOUT_HASH:

	case PACKET_FANOUT_LB:

	case PACKET_FANOUT_CPU:

		break;

	default:

		return -EINVAL;
@@ -606,14 +604,7 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 
			atomic_set(&match->sk_ref, 0);

			match->prot_hook.type = po->prot_hook.type;

			match->prot_hook.dev = po->prot_hook.dev;

			switch (type) {

			case PACKET_FANOUT_HASH:

				match->prot_hook.func = packet_rcv_fanout_hash;

				break;

			case PACKET_FANOUT_LB:

				match->prot_hook.func = packet_rcv_fanout_lb;

				break;

			}

			match->prot_hook.func = packet_rcv_fanout;

			match->prot_hook.af_packet_priv = match;

			dev_add_pack(&match->prot_hook);

			list_add(&match->list, &fanout_list);