icmp flood

typedef struct tcpheader{    USHORT        th_sport;    USHORT        th_dport;    unsigned int  th_seq;    unsigned int  th_ack;    unsigned char th_lenres;    unsigned char th_flag;    USHORT        th_win;    USHORT        th_sum;    USHORT        th_urp;}TCP_HEADER;