sniff packets in c

packet_sniff.c

int main()
{
    int dsize, saddr_size;
    struct sockaddr saddr;
    struct in_addr in;
     
    unsigned char *buf = (unsigned char *)malloc(65536);
     
    if((raw_socket = socket(AF_INET , SOCK_RAW , IPPROTO_TCP) < 0)
    {
        printf("Socket Error\n");
        return 1;
    }

    while(1)
    {
        saddr_size = sizeof saddr;
        dsize = recvfrom(sock_raw , buffer , 65536 , 0 , &saddr , &saddr_size);
        if(data_size < 0)
        {
            printf("Recvfrom error: failed to get packets\n");
            return 1;
        }

        // If we get here, process(buffer, dsize) ...
    }
    close(raw_socket);
}