add 203 codes

Blatt02/A203/arp_packet.h

@@ -0,0 +1,43 @@
+#ifndef ARP_PACKET_H
+#define ARP_PACKET_H
+
+#include <assert.h>
+#include <arpa/inet.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <linux/if_tun.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdint.h>
+#include "arp_packet_st.h"
+#include "util.h"
+
+#define IP_A_S 4
+#define OP_A_S 2
+
+#define SUCCESS 0
+#define FAILED -1
+#define UNEQUAL 1
+
+#define ARES_OP_REQ 0x0001
+#define ARES_OP_REP 0x0002
+#define ARES_HRD_ETHERNET 0x0001
+#define ETHER_T_ARP 0x0806
+#define ARES_PRO_IP 0x0800
+
+#define TB_L 100
+
+
+int parse_arp_packet(mac_hdr * hdr, pkt_data * pkt, uint8_t * buf, size_t size);
+
+int receive_arp_packet(mac_hdr * hdr, pkt_data * pkt, uint8_t * buf, size_t size, uint8_t * local_ip, uint8_t * local_mac);
+
+int send_arp_response(int tun_fd, uint8_t * resp_buffer, size_t length, const pkt_data * pkt, const mac_hdr * hdr);
+
+
+#endif