gistfile1.txt

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <stdint.h>
#include <errno.h>
#include <arpa/inet.h>
#include <linux/if_packet.h>
#include <sys/ioctl.h>
//#include <net/if.h>
#include <netinet/ether.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <linux/netdevice.h>
#define ARP 1
/* Define structures */
typedef struct {
    uint8_t mac_dest[6];
    uint8_t mac_src[6];
    uint16_t ether_type;
} eth_header_t;
typedef struct {
	uint16_t hardware_type;
	uint16_t protocol_type;
	uint8_t hardware_l;
	uint8_t protocol_l;
	uint16_t operation;
	uint8_t sender_hwa[6];
	uint8_t sender_ip[4];
	uint8_t target_hwa[6];
	uint8_t target_ip[4];
} arp_header_t;
/* End Structures*/

eth_header_t parse_eth_header(uint8_t *buffer) { //parse eth header
	int i = 0;
	eth_header_t tmp;
	for (i = 0; i < 6; i++) {
		tmp.mac_dest[i] = buffer[i];
	}
	buffer += 6;
	for (i = 0; i < 6; i++) {
		tmp.mac_src[i] = buffer[i];
	}
	tmp.ether_type = (buffer[7] << 8) | buffer[6];
	uint8_t *tmp_8 = (uint8_t * ) & tmp.ether_type;
	tmp_8[0] = buffer[6];
	tmp_8[1] = buffer[7];

	return tmp;
}

/* Reading function */
int sup_read(int protocol, uint8_t *buffer, int buffer_length) {
	int s;
	s = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
	if (s == -1) {
		printf("Erreur lors de l'ouverture de la socket");
	}
	uint8_t *rx_buff = (uint8_t *) malloc(1500);
	int exit = 1;
	int length = 0;
	while (exit) {
		length = recvfrom(s, rx_buff, 65535, 0, NULL, NULL);
		uint8_t *tmp1 = rx_buff;
		eth_header_t tmp_head = parse_eth_header(rx_buff);
		eth_header_t *eth_head = &tmp_head;
		eth_head->ether_type = htons(eth_head->ether_type);
		switch (eth_head->ether_type) {
		case 0x0806:
			if (protocol == ARP) {
				tmp1 = rx_buff;
				tmp1 += sizeof(eth_header_t);
				length -=sizeof(eth_header_t);
				memcpy(buffer,rx_buff,length);
				printf("This is an ARP frame");
				exit=0;
			}
			break;
		}
	}
	close(s);
	free(rx_buff);
	return length;
}
/*End reading*/


int main(){
  uint8_t *buffer = (uint8_t *) malloc(1500);
  while(1){
     sup_read(1, buffer, sizeof(buffer));
}
}