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: David S. Miller <davem@davemloft.net>

1 files changed, 28 insertions, 37 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 7ba6871a1942..41f0489ff665 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -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;
@@ -482,8 +489,8 @@ 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,
-                                  struct packet_type *pt, struct net_device *orig_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;
         unsigned int num = f->num_members;
@@ -496,35 +503,25 @@ static int packet_rcv_fanout_hash(struct sk_buff *skb, struct net_device *dev,
                 return 0;
         }
 
-        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;
+        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);
+                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);