基于统计的synflood攻击检测程序。用snort的plug-in功能，计算异常syn packet的个数，以检测攻击。把sp_tcp_synflood_check.c，sp_tcp_synflood_check.h添加snort的srcdetection-plugins。-using snort,detect synflood attack.sp_tcp_synflood_check.c，sp_tcp_synflood_check.h are added detection-plugins