net_sched: optimize tcf_match_indev()

tcf_match_indev() is called in fast path, it is not wise to
search for a netdev by ifindex and then compare by its name,
just compare the ifindex.

Also, dev->name could be changed by user-space, therefore
the match would be always fail, but dev->ifindex could
be consistent.

BTW, this will also save some bytes from the core struct of u32.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 15 deletions

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 50ea079..a2441fb 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -338,27 +338,27 @@ static inline int tcf_valid_offset(const struct sk_buff *skb,
 #include <net/net_namespace.h>
 
 static inline int
-tcf_change_indev(struct tcf_proto *tp, char *indev, struct nlattr *indev_tlv)
+tcf_change_indev(struct net *net, struct nlattr *indev_tlv)
 {
+	char indev[IFNAMSIZ];
+	struct net_device *dev;
+
 	if (nla_strlcpy(indev, indev_tlv, IFNAMSIZ) >= IFNAMSIZ)
 		return -EINVAL;
-	return 0;
+	dev = __dev_get_by_name(net, indev);
+	if (!dev)
+		return -ENODEV;
+	return dev->ifindex;
 }
 
-static inline int
-tcf_match_indev(struct sk_buff *skb, char *indev)
+static inline bool
+tcf_match_indev(struct sk_buff *skb, int ifindex)
 {
-	struct net_device *dev;
-
-	if (indev[0]) {
-		if  (!skb->skb_iif)
-			return 0;
-		dev = __dev_get_by_index(dev_net(skb->dev), skb->skb_iif);
-		if (!dev || strcmp(indev, dev->name))
-			return 0;
-	}
-
-	return 1;
+	if (!ifindex)
+		return true;
+	if  (!skb->skb_iif)
+		return false;
+	return ifindex == skb->skb_iif;
 }
 #endif /* CONFIG_NET_CLS_IND */