taglinefilesource code
ETH_HLEN124drivers/net/loopback.cdev->hard_header_len  = ETH_HLEN;    /* 14      */
ETH_HLEN175drivers/net/net_init.cdev->hard_header_len   = ETH_HLEN;
ETH_HLEN92net/ethernet/eth.cstruct ethhdr *eth = (struct ethhdr *)skb_push(skb,ETH_HLEN);
ETH_HLEN284net/ethernet/eth.cmemcpy(dest->data,src,sizeof(struct iphdr)+ETH_HLEN);  /* ethernet is always >= 34 */
ETH_HLEN285net/ethernet/eth.clength -= sizeof(struct iphdr) + ETH_HLEN;
ETH_HLEN286net/ethernet/eth.ciph=(struct iphdr*)(src+ETH_HLEN);
ETH_HLEN293net/ethernet/eth.cdest->csum=csum_partial_copy(src+sizeof(struct iphdr)+ETH_HLEN,dest->data+sizeof(struct iphdr)+ETH_HLEN,length,base);