taglinefilesource code
header_cache203drivers/net/net_init.cdev->header_cache = eth_header_cache;
header_cache96drivers/net/tunnel.cdev->header_cache=NULL;
header_cache168include/linux/netdevice.hvoid        (*header_cache)(struct device *dev, struct sock *sk, unsigned long saddr, unsigned long daddr);
header_cache2515net/ipv4/ip.cif(rt->rt_dev->header_cache && sk->ip_hcache_state!= -1)
header_cache2518net/ipv4/ip.crt->rt_dev->header_cache(rt->rt_dev,sk,saddr,daddr);