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