网络端口扫描技术原理分析与实现作者：李利均PAGEII摘要随着计算机在现代社会的广泛应用，计算机网络在人们工作和生活的各个领域占有越来越重要的地位。由于网络规模的迅速扩张和计算机系统的日益复杂，新的系统漏洞层出不穷。如何保证网络的安全运行已经成为一个亟待解决的问题。网络扫描技术是当前网络安全评估的重要组成部分，通过对网络的扫描，能够及时了解网络的运行状况及其存在的弱点，从而帮助网络管理员充分的了解网络的实际情况，并制定合适的安全策略，最终达到改善网络状况，增强网络安全系数的目的。同时，网络扫描技术也常为入侵者所利用，通过扫描远程主机或网络，能够探测攻击目标的软硬件配置信息，为制订攻击策略做准备。本文详细研究了计算机端口扫描技术的优缺点，并采用多线程技术结合TCP全连接扫描实现了基于C语言和WindowsSocket编程的网络端口扫描程序。程序模拟入侵者对目标主机的多线程入侵扫描，快速、及时、准确地检测出目标主机的端口状态，为网络系统管理员评测系统安全性提供数据支持。关键词：多线程；TCP全连接；同步；Winsock；TCP/IPAbstractWiththewiderangeofapplicationsofthecomputerinmodernsociety,thecomputernetworkplaysamoreandmoreimportantroleinpeople’sworkingandliving.Duetotherapidexpansionofthenetworksizeandtheincreasingcomplexityofthecomputersystems,anendlessstreamofnewvulnerabilitieswillbefound.Howtoensurethesafeoperationofthenetworkhasbecomeanissue.Networkscanningtechnologyisanimportantcomponentofthecurrentnetworksecurityassessment.Byscanningthenetworktokeepabreastoftheoperationofthenetworkanditsweaknesses,therebyhelpingnetworkadministratorstofullyunderstandtheactualsituationofthenetworkandtodevelopappropriatesecuritypolicy,andultimatelyachievethepurposeofimprovingthenetworkconditions,andenhancingthenetworksecuritycoefficient.Atthesametime,networkscanningtechnologyisalsooftenusedbyintruders.Byscanningtheremotehostornetwork,intruderscandetectthehardwareandsoftwareconfigurationinformationofthetarget.Therebyformulatethestrategiestoprepareattack.Inthispaper,Igiveadetailedstudyoftheadvantagesanddisadvantagesofcomputerportscanningtechnology,andusethemulti-threadingtechnologyandTCPconnectscanningtechnologytoachieveanetworkportscannerwhichisbasedontheCprogramminglanguageandWindowsSocket.Theproceduresimulatetheinvadersonthetargethost'sinvasionofmulti-threadedscanning,rapidly,timelyandaccuratelydetectthecomputerportstatusofthetargethostinordertoprovidedatatothenetworksystemadministratortoevaluatethesecuritycoefficientofsystem.Keywords:multi-threaded;TCPconnect;synchronization;Winsock;TCP/IPTOC\o"1-3"\h\z\uHYP