#include?“get_internet_time.h“

using?namespace?std;

/*
Name:		FindHostIP
Function:	get?IP?address?across?ServerName
params:		const?char?*pServerName
return:		IPNumber
*/

IPNumber?FindHostIP（const?char?*pServerName）
{
	HOSTENT?*pHostent;

	//?Get?hostent?structure?for?hostname:
	if?（!（pHostent?=?gethostbyname（pServerName）））
		throw?HRException（“could?not?resolve?hostname.“）;

	//?Extract?primary?IP?address?from?hostent?structure:
	if?（pHostent->h_addr_list?&&?pHostent->h_addr_list[0]）
		return?*reinterpret_cast（pHostent->h_addr_list[0]）;

	return?0;
}


/*
Name:		FillSockAddr
Function:	Fill?socket?with?address（serverName）
params:		sockaddr_in?*pSockAddr?const?char?*pServerName?int?portNumber
return:		None
*/
void?FillSockAddr（sockaddr_in?*pSockAddr?const?char?*pServerName?int?portNumber）
{
	//?Set?family?port?and?find?IP
	pSockAddr->sin_family?=?AF_INET;
	pSockAddr->sin_port?=?htons（portNumber）;
	pSockAddr->sin_addr.S_un.S_addr?=?FindHostIP（pServerName）;
}




/*
Name:		RequestHeaders
Function:	Key?Function?Request?time?from?time?server
params:		const?char?*pServername?time_t?*timeRecv
return:		bool?if?get?internet?time?successfullyreturn?trueelsereturn?false
*/
bool?RequestHeaders（const?char?*pServername?time_t?*timeRecv）
{
	int?slen?=?0;
	//time_t?timeRecv;
	SOCKET??????hSocket?=?INVALID_SOCKET;
	char????????recvBuf[REC_BUFFER_SIZE];
	sockaddr_in?sockAddr?=?{?0?};
	bool????????bSuccess?=?true;


	try{
		//?Lookup?hostname?and?fill?sockaddr_in?structure:
		FillSockAddr（&sockAddr?pServername?SERVER_PORT）;

		//?Create?socket
		if?（（hSocket?=?socket（AF_INET?SOCK_DGRAM?IPPROTO_UDP））?==?INVALID_SOCKET）
			throw?HRException（“could?not?create?socket.“）;


		//?Connect?to?server
		if?（connect（hSocket?reinterpret_cast（&sockAddr）?sizeof（sockAddr））?!=?0）
			throw?HRException（“could?not?connect.“）;
		//cout?<

		//?send?request?part?1
		if?（send（hSocket?msg?sizeof（msg）?0）?==?SOCKET_ERROR）
			throw?HRException（“failed?to?send?data.“）;


		//cout?<		//?Loop?to?print?all?data
		slen?=?recv（hSocket?recvBuf?REC_BUFFER_SIZE?0）;
		//part?where?we?take?time?out?of?recvBuf???????
		*timeRecv?=?ntohl（（（time_t*）recvBuf）[4]）;
		if?（*timeRecv>0）*timeRecv?-=?2208988800U;

	}
	catch?（HRException?e）{
		cerr?<		bSuccess?=?false;
	}


	if?（hSocket?!=?INVALID_SOCKET）{
		closesocket（hSocket）;
	}

	return?bSuccess;
}



/*
Name:		time_t_2_tm
Function:	Transfer?time_t?to?tm
params:		const?time_t?*tt?struct?tm?*tim
return:		None
Author:		Leo?Ma
Date:		2019.09.17
*/
void?time_t_2_tm（const?time_t?*tt?struct?tm?*tim）
{
	tim?=?localtime（tt）;
	tim->tm_year?+=?1900;
	tim->tm_mon?+=?1;
}



/*
Name:		get_internet_time
Function:	check?windows?socket?version?and?get?internet

?屬性????????????大小?????日期????時(shí)間???名稱(chēng)
-----------?---------??----------?-----??----
?????文件????????5175??2019-09-18?14:46??get?internet?time\get_internet_time.cpp
?????文件????????1419??2019-09-17?16:58??get?internet?time\get_internet_time.h
?????目錄???????????0??2019-09-18?14:47??get?internet?time\