[NET]: Avoid unnecessary cloning for ingress filtering
As it is we always invoke pt_prev before ing_filter, even if there are no
ingress filters attached. This can cause unnecessary cloning in pt_prev.
This patch changes it so that we only invoke pt_prev if there are ingress
filters attached.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 99b7bda..39aba48 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1949,28 +1949,52 @@
struct Qdisc *q;
struct net_device *dev = skb->dev;
int result = TC_ACT_OK;
+ u32 ttl = G_TC_RTTL(skb->tc_verd);
- if (dev->qdisc_ingress) {
- __u32 ttl = (__u32) G_TC_RTTL(skb->tc_verd);
- if (MAX_RED_LOOP < ttl++) {
- printk(KERN_WARNING "Redir loop detected Dropping packet (%d->%d)\n",
- skb->iif, skb->dev->ifindex);
- return TC_ACT_SHOT;
- }
-
- skb->tc_verd = SET_TC_RTTL(skb->tc_verd,ttl);
-
- skb->tc_verd = SET_TC_AT(skb->tc_verd,AT_INGRESS);
-
- spin_lock(&dev->ingress_lock);
- if ((q = dev->qdisc_ingress) != NULL)
- result = q->enqueue(skb, q);
- spin_unlock(&dev->ingress_lock);
-
+ if (MAX_RED_LOOP < ttl++) {
+ printk(KERN_WARNING
+ "Redir loop detected Dropping packet (%d->%d)\n",
+ skb->iif, dev->ifindex);
+ return TC_ACT_SHOT;
}
+ skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
+ skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
+
+ spin_lock(&dev->ingress_lock);
+ if ((q = dev->qdisc_ingress) != NULL)
+ result = q->enqueue(skb, q);
+ spin_unlock(&dev->ingress_lock);
+
return result;
}
+
+static inline struct sk_buff *handle_ing(struct sk_buff *skb,
+ struct packet_type **pt_prev,
+ int *ret, struct net_device *orig_dev)
+{
+ if (!skb->dev->qdisc_ingress)
+ goto out;
+
+ if (*pt_prev) {
+ *ret = deliver_skb(skb, *pt_prev, orig_dev);
+ *pt_prev = NULL;
+ } else {
+ /* Huh? Why does turning on AF_PACKET affect this? */
+ skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
+ }
+
+ switch (ing_filter(skb)) {
+ case TC_ACT_SHOT:
+ case TC_ACT_STOLEN:
+ kfree_skb(skb);
+ return NULL;
+ }
+
+out:
+ skb->tc_verd = 0;
+ return skb;
+}
#endif
int netif_receive_skb(struct sk_buff *skb)
@@ -2021,21 +2045,9 @@
}
#ifdef CONFIG_NET_CLS_ACT
- if (pt_prev) {
- ret = deliver_skb(skb, pt_prev, orig_dev);
- pt_prev = NULL; /* noone else should process this after*/
- } else {
- skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
- }
-
- ret = ing_filter(skb);
-
- if (ret == TC_ACT_SHOT || (ret == TC_ACT_STOLEN)) {
- kfree_skb(skb);
+ skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
+ if (!skb)
goto out;
- }
-
- skb->tc_verd = 0;
ncls:
#endif