int pkt_shift_data(struct packet *pkt, unsigned int from, unsigned int to, unsigned int len);
int pkt_tcp_change_seqno(int rel_seq, int rel_ackseq);
int pkt_tcp_set_seqno(unsigned int seq, unsigned int ackseq);
int pkt_shift_data(struct packet *pkt, unsigned int from, unsigned int to, unsigned int len);
int pkt_tcp_change_seqno(int rel_seq, int rel_ackseq);
int pkt_tcp_set_seqno(unsigned int seq, unsigned int ackseq);