+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_orphan_frags])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_get_hash])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_clear_hash])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [l4_rxhash])