114 lines
2 KiB
C
114 lines
2 KiB
C
|
/*++
|
||
|
|
|
||
|
|
Copyright (C) 1999 Microsoft Corporation
|
||
|
|
|
||
|
|
Module Name:
|
||
|
|
|
||
|
|
isdhcp.c
|
||
|
|
|
||
|
|
Abstract:
|
||
|
|
|
||
|
|
test program to see if a DHCP server is around or not.
|
||
|
|
|
||
|
|
Environment:
|
||
|
|
|
||
|
|
Win2K+
|
||
|
|
|
||
|
|
--*/
|
||
|
|
|
||
|
|
#include <nt.h>
|
||
|
|
#include <ntrtl.h>
|
||
|
|
#include <nturtl.h>
|
||
|
|
#include <windows.h>
|
||
|
|
#include <dhcpcapi.h>
|
||
|
|
#include <iprtrmib.h>
|
||
|
|
#include <iphlpapi.h>
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <winsock2.h>
|
||
|
|
|
||
|
|
BOOL
|
||
|
|
IsDHCPAvailableOnInterface(DWORD ipaddress)
|
||
|
|
/*++
|
||
|
|
|
||
|
|
Routine Description:
|
||
|
|
|
||
|
|
This routine attempts to check if a dhcp
|
||
|
|
server is around by trying to get a dhcp lease.
|
||
|
|
|
||
|
|
If that fails, then it assume that no dhcp server
|
||
|
|
is around.
|
||
|
|
|
||
|
|
Return Values:
|
||
|
|
|
||
|
|
TRUE -- DHCP server is around
|
||
|
|
FALSE -- DHCP server not around
|
||
|
|
|
||
|
|
In case of internal failures, it will return FALSE
|
||
|
|
|
||
|
|
--*/
|
||
|
|
{
|
||
|
|
DWORD Error = 0;
|
||
|
|
DHCP_CLIENT_UID DhcpClientUID =
|
||
|
|
{
|
||
|
|
(BYTE*)"ISDHCP",
|
||
|
|
6
|
||
|
|
};
|
||
|
|
DHCP_OPTION_LIST DummyOptList;
|
||
|
|
LPDHCP_LEASE_INFO LeaseInfo = 0;
|
||
|
|
LPDHCP_OPTION_INFO DummyOptionInfo = 0;
|
||
|
|
BOOL found = FALSE;
|
||
|
|
|
||
|
|
if( ipaddress == INADDR_ANY ||
|
||
|
|
ipaddress == INADDR_LOOPBACK ||
|
||
|
|
ipaddress == 0x0100007f)
|
||
|
|
{
|
||
|
|
//
|
||
|
|
// oops. not a usable address
|
||
|
|
//
|
||
|
|
return FALSE;
|
||
|
|
}
|
||
|
|
|
||
|
|
LeaseInfo = NULL;
|
||
|
|
Error = DhcpLeaseIpAddress(
|
||
|
|
RtlUlongByteSwap(ipaddress),
|
||
|
|
&DhcpClientUID,
|
||
|
|
0,
|
||
|
|
&DummyOptList,
|
||
|
|
&LeaseInfo,
|
||
|
|
&DummyOptionInfo);
|
||
|
|
|
||
|
|
if( NO_ERROR != Error )
|
||
|
|
{
|
||
|
|
//
|
||
|
|
// lease request failed.
|
||
|
|
//
|
||
|
|
|
||
|
|
if( ERROR_ACCESS_DENIED == Error )
|
||
|
|
{
|
||
|
|
//
|
||
|
|
// We only get access denied if the dhcp server
|
||
|
|
// is around to NAK it. So we have found a dhcp
|
||
|
|
// server
|
||
|
|
//
|
||
|
|
found = TRUE;
|
||
|
|
}
|
||
|
|
return found;
|
||
|
|
}
|
||
|
|
|
||
|
|
if( LeaseInfo->DhcpServerAddress != INADDR_ANY &&
|
||
|
|
LeaseInfo->DhcpServerAddress != INADDR_NONE )
|
||
|
|
{
|
||
|
|
//
|
||
|
|
// Valid address, so dhcp is there.
|
||
|
|
//
|
||
|
|
|
||
|
|
DhcpReleaseIpAddressLease(
|
||
|
|
RtlUlongByteSwap(ipaddress),
|
||
|
|
LeaseInfo);
|
||
|
|
|
||
|
|
found = TRUE;
|
||
|
|
}
|
||
|
|
|
||
|
|
return found;
|
||
|
|
}
|