/*?$Id:?checksum.cv?1.2?2001/01/02?08:06:00?roesch?Exp?$?*/
/*
**?Copyright?（C）?1998199920002001?Martin?Roesch?
**
**?This?program?is?free?software;?you?can?redistribute?it?and/or?modify
**?it?under?the?terms?of?the?GNU?General?Public?License?as?published?by
**?the?Free?Software?Foundation;?either?version?2?of?the?License?or
**?（at?your?option）?any?later?version.
**
**?This?program?is?distributed?in?the?hope?that?it?will?be?useful
**?but?WITHOUT?ANY?WARRANTY;?without?even?the?implied?warranty?of
**?MERCHANTABILITY?or?FITNESS?FOR?A?PARTICULAR?PURPOSE.??See?the
**?GNU?General?Public?License?for?more?details.
**
**?You?should?have?received?a?copy?of?the?GNU?General?Public?License
**?along?with?this?program;?if?not?write?to?the?Free?Software
**?Foundation?Inc.?59?Temple?Place?-?Suite?330?Boston?MA?02111-1307?USA.
*/

#include?“checksum.h“

/*
?*?Function:?checksum（u_int16_t?*?u_int32_t?u_int16_t?*?u_int32_t）
?*
?*?Purpose:?Huh?huh?math....
?*
?*?Arguments:?b1???=>?pointer?to?data?set?one
?*????????????len1?=>?length?of?data?set?one
?*????????????b2???=>?pointer?to?data?set?two
?*????????????len2?=>?length?of?data?set?two
?*
?*?Returns:?csum?=>?the?calculated?checksum?for?the?given?data
?*/
u_int16_t?checksum（u_int16_t?*b1?u_int32_t?len1?u_int16_t?*b2?u_int32_t?len2）
{
????u_int32_t?sum?=?0;

????if（b1?!=?（u_int16_t?*）NULL）?
????{
????????while（len1?>?1）?
????????{
????????????sum?+=?*（（u_int16_t?*）b1?++）;

????????????if（sum?&?0x80000000）
????????????{
????????????????sum?=?（sum?&?0xffff）?+?（sum?>>?16）;
????????????}

????????????len1?-=?2;
????????}
????
????????/*?we‘ll?have?problems?if?b2?exists?and?len1?is?odd?*/
????????if（len1）
????????{
???????????sum?+=?（u_int16_t）?*?（u_int8_t*）?b1;
????????}
????}

????if（b2?!=?（u_int16_t*）NULL）?
????{
????????while（len2?>?1）?
????????{
????????????sum?+=?*（（u_int16_t*）b2?++）;

????????????if（sum?&?0x80000000）
????????????{
????????????????sum?=?（sum?&?0xffff）?+?（sum?>>?16）;
????????????}

????????????len2?-=?2;
????????}

????????if（len2）
????????{
????????????sum?+=?（u_int16_t）?*?（u_int8_t*）?b2;
????????}
????}

????while（sum?>>?16）
????????sum?=?（sum?&?0xffff）?+?（sum?>>?16）;

????return?~sum;
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????1037??2000-10-31?11:36??網絡入侵檢測snort\acconfig.h

?????文件???????7205??2001-01-05?13:22??網絡入侵檢測snort\aclocal.m4

?????文件????????269??2000-10-29?01:23??網絡入侵檢測snort\AUTHORS

?????文件???????3124??2000-11-20?00:41??網絡入侵檢測snort\backdoor-lib

?????文件???????1005??2001-01-18?05:40??網絡入侵檢測snort\BUGS

?????文件???????3718??2000-10-29?01:35??網絡入侵檢測snort\cdefs.h

?????文件??????30111??2001-01-18?08:30??網絡入侵檢測snort\ChangeLog

?????文件???????2294??2001-01-02?02:06??網絡入侵檢測snort\checksum.c

?????文件???????1278??2001-01-02?02:06??網絡入侵檢測snort\checksum.h

?????文件??????21063??2000-10-29?01:23??網絡入侵檢測snort\config.guess

?????文件???????3353??2001-02-05?09:01??網絡入侵檢測snort\config.h

?????文件???????2659??2001-01-26?19:03??網絡入侵檢測snort\config.h.in

?????文件??????20163??2000-10-29?01:23??網絡入侵檢測snort\config.sub

?????文件?????109328??2001-01-30?20:53??網絡入侵檢測snort\configure

?????文件??????15219??2001-01-30?20:53??網絡入侵檢測snort\configure.in

?????文件??????18329??2000-10-29?01:23??網絡入侵檢測snort\COPYING

?????文件???????6830??2001-01-02?10:14??網絡入侵檢測snort\CREDITS

?????文件???????3881??2000-11-20?00:41??網絡入侵檢測snort\ddos-lib

?????文件??????41572??2001-02-05?07:38??網絡入侵檢測snort\decode.c

?????文件??????20027??2001-02-01?10:40??網絡入侵檢測snort\decode.h

?????文件???????1236??2000-11-20?00:41??網絡入侵檢測snort\finger-lib

?????文件???????2298??2000-11-20?00:41??網絡入侵檢測snort\ftp-lib

?????文件??????13064??2001-01-02?17:35??網絡入侵檢測snort\INSTALL

?????文件???????5834??2000-10-29?01:23??網絡入侵檢測snort\install-sh

?????文件??????18329??2001-01-02?01:37??網絡入侵檢測snort\LICENSE

?????文件??????64553??2001-02-01?10:43??網絡入侵檢測snort\log.c

?????文件???????3083??2001-01-02?02:06??網絡入侵檢測snort\log.h

?????文件???????2853??2001-01-05?19:27??網絡入侵檢測snort\Makefile.am

?????文件??????14549??2001-01-26?19:03??網絡入侵檢測snort\Makefile.in

?????文件???????6232??2000-11-20?00:41??網絡入侵檢測snort\misc-lib

............此處省略300個文件信息