这几天在用MASM32按Time Protocol（RFC868）协议编写网络对时程序，现在基本完成了。将其中一些有用的函数代码整理了一下。
我们需要将本地系统时间转换为UTC格式发送给时间服务器，相关转换代码如下：
BaseTimeLow equ 0D53E8000h BaseTimeHigh equ 19DB1DEh ;::::::::::::::::::::::::::::::::::::::::::::::::::: FileTime2DateStamp proc lpFileTime: dword ;::::::::::::::::::::::::::::::::::::::::::::::::::: mov ecx, lpFileTime mov eax, [ecx] mov edx, [ecx+4] sub eax, BaseTimeLow sbb edx, BaseTimeHigh mov ecx, 10000000 div ecx RET FileTime2DateStamp endp ;:::::::::::::::::::::::::::::::::::::::: GetLocalTimeStamp proc ;:::::::::::::::::::::::::::::::::::::::: local stSystemTime: SYSTEMTIME local stFileTime: FILETIME invoke GetSystemTime, addr stSystemTime invoke SystemTimeToFileTime, addr stSystemTime, addr stFileTime invoke FileTime2DateStamp, addr stFileTime ret GetLocalTimeStamp endp
时间服务器返回的是从1900年1月1日午夜到现在的秒数，将其转换为本地时间的相关代码如下：
;:::::::::::::::::::::::::::::::::::::::::::::::::::: _MemCpy proc lpD, lpS, dwSize ;:::::::::::::::::::::::::::::::::::::::::::::::::::: mov esi, lpS mov edi, lpD mov ecx, dwSize rep movsb ret _MemCpy endp g_szFmtDateTime db "%d-%d-%d %d:%d:%d", 0 ;:::::::::::::::::::::::::::::::::::::::::::::::::::: printDateTime proc dwTimeStamp: dword ;:::::::::::::::::::::::::::::::::::::::::::::::::::: local buf[30]: byte local stSysTime: SYSTEMTIME local stFileTime: FILETIME local stLocFileTime: FILETIME local li: LARGE_INTEGER invoke RtlZeroMemory, addr stSysTime, sizeof stSysTime mov stSysTime.wYear, 1900 mov stSysTime.wMonth, 1 mov stSysTime.wDay, 1 invoke SystemTimeToFileTime, addr stSysTime, addr stFileTime invoke _MemCpy, addr li, addr stFileTime, sizeof stFileTime mov eax, dwTimeStamp mov edx, 10000000 mul edx; edx=10000000 lea edi, li.QuadPart add [edi], eax adc [edi+4], edx invoke _MemCpy, addr stFileTime, addr li, sizeof li invoke FileTimeToLocalFileTime, addr stFileTime, addr stLocFileTime lea edi, stSysTime;push edi invoke FileTimeToSystemTime, addr stLocFileTime, edi ;edi=addr stSysTime ;pop edi movzx eax, (SYSTEMTIME ptr [edi]).wYear movzx ebx, (SYSTEMTIME ptr [edi]).wMonth movzx ecx, (SYSTEMTIME ptr [edi]).wDay movzx edx, (SYSTEMTIME ptr [edi]).wHour movzx esi, (SYSTEMTIME ptr [edi]).wMinute movzx edi, (SYSTEMTIME ptr [edi]).wSecond invoke wsprintf, addr buf, addr g_szFmtDateTime, eax, ebx, ecx,edx, esi, edi invoke StdOut, addr buf ret printDateTime endp
