获取端口列表链的下一项(端口范围)：
int libnet_plist_chain_next_pair(struct libnet_plist_chain *plist,u_short *bport, u_short *eport);
端口列表链输出显示：
int libnet_plist_chain_dump(struct libnet_plist_chain *plist);
获取端口列表链：
u_char *libnet_plist_chain_dump_string(struct libnet_plist_chain *plist);
端口列表链内存释放：
void libnet_plist_chain_free(struct libnet_plist_chain *plist);