taglinefilesource code
ip_hcache_stamp203include/net/sock.hunsigned long    ip_hcache_stamp;  /* Header cache stamp */
ip_hcache_stamp228net/ethernet/eth.csk->ip_hcache_stamp=arp_cache_stamp;
ip_hcache_stamp2500net/ipv4/ip.cif(sk->ip_hcache_ver==NULL || sk->ip_hcache_stamp!=*sk->ip_hcache_ver)