提交 849b920e 编写于 作者: A Alexander Duyck 提交者: David S. Miller

etherdev: Avoid unnecessary byte swap in check for Ethertype

This change takes advantage of the fact that ETH_P_802_3_MIN is aligned to
512 so as a result we can actually ignore the lower 8b when comparing the
Ethertype to ETH_P_802_3_MIN.  This allows us to avoid a byte swap by simply
masking the value and comparing it to the byte swapped value for
ETH_P_802_3_MIN.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
上级 82a584b7
......@@ -178,7 +178,7 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
if (unlikely(netdev_uses_dsa(dev)))
return htons(ETH_P_XDSA);
if (likely(ntohs(eth->h_proto) >= ETH_P_802_3_MIN))
if (likely((eth->h_proto & htons(0xFF00)) >= htons(ETH_P_802_3_MIN)))
return eth->h_proto;
/*
......
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