ntpclient.c File Reference

#include "w32time.h"
#include <winsock2.h>

Include dependency graph for ntpclient.c:

Go to the source code of this file.

Classes
struct	_INFO

Macros
#define	TIMEOUT   4000 /* 4 second timeout */

Typedefs
typedef struct _INFO	INFO
typedef struct _INFO *	PINFO

Functions
static BOOL	InitConnection (PINFO pInfo, LPSTR lpAddress)
static VOID	DestroyConnection (VOID)
static BOOL	GetTransmitTime (PTIMEPACKET ptp)
static BOOL	SendData (PINFO pInfo)
static ULONG	ReceiveData (PINFO pInfo)
ULONG	GetServerTime (LPWSTR lpAddress)

Macro Definition Documentation

TIMEOUT

#define TIMEOUT   4000 /* 4 second timeout */

Definition at line 12 of file ntpclient.c.

Typedef Documentation

INFO

typedef struct _INFO INFO

PINFO

typedef struct _INFO * PINFO

Function Documentation

DestroyConnection()

static VOID DestroyConnection ( VOID  )

static

Definition at line 61 of file ntpclient.c.

{
    WSACleanup();
}

Referenced by GetServerTime().

GetServerTime()

ULONG GetServerTime

(

LPWSTR

lpAddress

)

Definition at line 138 of file ntpclient.c.

{
    PINFO pInfo;
    LPSTR lpAddr;
    DWORD dwSize = wcslen(lpAddress) + 1;
    ULONG ulTime = 0;
 
    pInfo = (PINFO)HeapAlloc(GetProcessHeap(),
                             0,
                             sizeof(INFO));
    lpAddr = (LPSTR)HeapAlloc(GetProcessHeap(),
                              0,
                              dwSize);
 
    if (pInfo && lpAddr)
    {
        if (WideCharToMultiByte(CP_ACP,
                                0,
                                lpAddress,
                                -1,
                                lpAddr,
                                dwSize,
                                NULL,
                                NULL))
        {
            if (InitConnection(pInfo, lpAddr))
            {
                if (SendData(pInfo))
                {
                    ulTime = ReceiveData(pInfo);
                }
            }
 
            DestroyConnection();
        }
    }
 
    if (pInfo)
        HeapFree(GetProcessHeap(), 0, pInfo);
    if (lpAddr)
        HeapFree(GetProcessHeap(), 0, lpAddr);
 
    return ulTime;
}

Referenced by SetTime().

GetTransmitTime()

static BOOL GetTransmitTime ( PTIMEPACKET  ptp )

static

Definition at line 68 of file ntpclient.c.

{
    return TRUE;
}

Referenced by SendData().

InitConnection()

static BOOL InitConnection ( PINFO  pInfo, LPSTR  lpAddress  )

static

Definition at line 25 of file ntpclient.c.

{
    WSADATA wsaData;
    HOSTENT *he;
    INT Ret;
 
    Ret = WSAStartup(MAKEWORD(2, 2),
                     &wsaData);
    if (Ret != 0)
        return FALSE;
 
    pInfo->Sock = socket(AF_INET,
                         SOCK_DGRAM,
                         0);
    if (pInfo->Sock == INVALID_SOCKET)
        return FALSE;
 
    /* Setup server info */
    he = gethostbyname(lpAddress);
    if (he != NULL)
    {
        /* Setup server socket info */
        ZeroMemory(&pInfo->ntpAddr, sizeof(SOCKADDR_IN));
        pInfo->ntpAddr.sin_family = AF_INET; // he->h_addrtype;
        pInfo->ntpAddr.sin_port = htons(NTPPORT);
        pInfo->ntpAddr.sin_addr = *((struct in_addr *)he->h_addr);
    }
    else
        return FALSE;
 
    return TRUE;
}

Referenced by GetServerTime().

ReceiveData()

static ULONG ReceiveData ( PINFO  pInfo )

static

Definition at line 102 of file ntpclient.c.

{
    TIMEVAL timeVal;
    FD_SET readFDS;
    INT Ret;
    ULONG ulTime = 0;
 
    /* Monitor socket for incoming connections */
    FD_ZERO(&readFDS);
    FD_SET(pInfo->Sock, &readFDS);
 
    /* Set timeout values */
    timeVal.tv_sec  = TIMEOUT / 1000;
    timeVal.tv_usec = TIMEOUT % 1000;
 
    /* Check for data on the socket for TIMEOUT millisecs */
    Ret = select(0, &readFDS, NULL, NULL, &timeVal);
 
    if ((Ret != SOCKET_ERROR) && (Ret != 0))
    {
        Ret = recvfrom(pInfo->Sock,
                       (char *)&pInfo->RecvPacket,
                       sizeof(pInfo->RecvPacket),
                       0,
                       NULL,
                       NULL);
 
        if (Ret != SOCKET_ERROR)
            ulTime = ntohl(pInfo->RecvPacket.TransmitTimestamp.dwInteger);
    }
 
    return ulTime;
}

Referenced by GetServerTime(), KdVmKdVmExchangeData(), and KdVmSendReceive().

SendData()

static BOOL SendData ( PINFO  pInfo )

static

Definition at line 76 of file ntpclient.c.

{
    TIMEPACKET tp = { 0, 0 };
    INT Ret;
 
    ZeroMemory(&pInfo->SendPacket, sizeof(pInfo->SendPacket));
    pInfo->SendPacket.LiVnMode = 0x1b;        /* 0x1b = 011 011 - version 3 , mode 3 (client) */
    if (!GetTransmitTime(&tp))
        return FALSE;
    pInfo->SendPacket.TransmitTimestamp = tp;
 
    Ret = sendto(pInfo->Sock,
                 (char *)&pInfo->SendPacket,
                 sizeof(pInfo->SendPacket),
                 0,
                 (SOCKADDR *)&pInfo->ntpAddr,
                 sizeof(SOCKADDR_IN));
 
    if (Ret == SOCKET_ERROR)
        return FALSE;
 
    return TRUE;
}

Referenced by GetServerTime(), KdpSendWaitContinue(), and test_IcmpSendEcho().