ARP 헤더

 

ARP 헤더

☞ 주소 결정 프로토콜 (Address Resolution Protocol)            struct  ether_arp  #include <netinet/if_ether.h>    struct  ether_arp  {           struct  arphdr ea_hdr;                /* fixed-size header */           u_int8_t arp_sha[ETH_ALEN];     /* sender hardware address */           u_int8_t arp_spa[4];                   /* sender protocol address */           u_int8_t arp_tha[ETH_ALEN];      /* target hardware address */           u_int8_t arp_tpa[4];                    /* target protocol address */  };      struct arphdr  #include <net/if_arp.h>     struct arphdr  {        unsigned short int ar_hrd;      /* Format of hardware address.  */        unsigned short int ar_pro;      /* Format of protocol address.  */        unsigned char ar_hln;           /* Length of hardware address.  */        unsigned char ar_pln;            /* Length of protocol address.  */        unsigned short int ar_op;       /* ARP opcode (command).  */  };

ARP 헤더 출력 함수

void HPreARP(PACKET *stpPkt) {    struct ether_arp *stpARP;  if(0 == stpPkt)  {        return;  }  else if(0 == stpPkt->stpARP)  {       return;  }  else  {        stpARP = stpPkt->stpARP; //ARP 헤더의 시작 주소를 넘겨줌  }    printf("HARDWARE IDentifier : [");  switch(ntohs(stpARP->ea_hdr.ar_hrd))  {   case ARPHRD_NETROM:         printf("NET/ROM pseud]\n");         break;        case ARPHRD_ETHER :         printf("Ethernet 10/100Mbps]\n");         break;        case ARPHRD_EETHER:       printf("Experimental Ethernet]\n");       break;        case ARPHRD_AX25:       printf("AX.25 Level 2]\n");       break;        case ARPHRD_PRONET:       printf("PROnet token ring]\n");       break;        case ARPHRD_CHAOS:       printf("Chaosnet]\n");       break;        case ARPHRD_IEEE802:       printf("IEEE 802.2 Ethernet/TR/TB]\n");       break;        case ARPHRD_ARCNET:       printf("ARCnet]\n");       break;        case ARPHRD_APPLETLK:       printf("APPLEtalk]\n");       break;        case ARPHRD_DLCI:       printf("Frame Relay DLCI]\n");       break;        case ARPHRD_ATM:       printf("ATM]\n");       break;        case ARPHRD_METRICOM:       printf("Metricom STRIP]\n");       break;          default:    printf("Not Support Type...]\n");    break;    }    printf("Format of protocol address : %d\n", ntohs(stpARP->ea_hdr.ar_pro));  printf("Length of hardware address : %d\n", stpARP->ea_hdr.ar_hln);  printf("Length of protocol address : %d\n", stpARP->ea_hdr.ar_pln);    printf("ARP Comand      :["); /* ARP protocol opcodes. */  switch(ntohs(stpARP->ea_hdr.ar_op))  {     case ARPOP_REQUEST:       printf("ARP Request]\n");       break;       case ARPOP_REPLY:       printf("ARP reply]\n");       break;       case ARPOP_RREQUEST:       printf("RARP request]\n");       break;       case ARPOP_RREPLY:       printf("RARP reply]\n");       break;       case ARPOP_InREQUEST:       printf("InARP request]\n");       break;       case ARPOP_InREPLY:       printf("InARP reply]\n");       break;      case ARPOP_NAK :       printf("(ATM)ARP NAK]\n");       break;       default:    printf("Unknown Type...]\n");    break;  }  printf(" MAC [%02X:%02X:%02X:%02X:%02X:%02X] -> "                                                                                     , stpARP->arp_sha[0]                                                                                     , stpARP->arp_sha[1]                                                                                     , stpARP->arp_sha[2]                                                                                     , stpARP->arp_sha[3]                                                                                     , stpARP->arp_sha[4]                                                                                     , stpARP->arp_sha[5] );  printf("[%02X:%02X:%02X:%02X:%02X:%02X]\n"                                                                                     , stpARP->arp_tha[0]                                                                                     , stpARP->arp_tha[1]                                                                                     , stpARP->arp_tha[2]                                                                                     , stpARP->arp_tha[3]                                                                                     , stpARP->arp_tha[4]                                                                                     , stpARP->arp_tha[5]);    printf("IP : [%s] -> ", inet_ntoa(*(struct in_addr *)&stpARP->arp_spa));  printf("[%s]\n", inet_ntoa(*(struct in_addr *)&stpARP->arp_tpa));   }