Ethernetヘッダ(DIX規格) linux/if_ehter.h struct ethhdr { unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ unsigned char h_source[ETH_ALEN]; /* source ether addr */ unsigned short h_proto; /* packet type ID field */ }; IPv4ヘッダ netinet/ip.h struct iphdr { #if __BYTE_ORDER == __LITTLE_ENDIAN unsigned int ihl:4; unsigned int version:4; #elif __BYTE_ORDER == __BIG_ENDIAN unsigned int version:4; un