VARPTR function ... how to use ???

[Guy Fournier]

Hi,

I'm not familiar with varptr with type/end type, someone have the kindness to explain how to print the result of that structure ? I never had to use this function before, sorry for that question but I would like to understand how to do that !

Thank you for your answer.

Guy

ex:
EnumDhcpServers.Version
EnumDhcpServers.ServerName
etc...

Code Select Expand


#COMPILE EXE
#DIM ALL

#INCLUDE "f:\dns\dhcpsapi.inc"
FUNCTION PBMAIN () AS LONG

' // Serie = 28 bytes
'TYPE DHCPDS_SERVER DWORD
'   Version       AS DWORD          ' DWORD // version of this structure -- currently zero
'   ServerName    AS WSTRINGZ PTR   ' LPWSTR // [DNS?] unique name for server
'   ServerAddress AS DWORD          ' DWORD // ip address of server
'   Flags         AS DWORD          ' DWORD // additional info -- state
'   State         AS DWORD          ' DWORD // not used ...
'   DsLocation    AS WSTRINGZ PTR   ' LPWSTR // ADsPath to server object
'   DsLocType     AS DWORD          ' DWORD // path relative? absolute? diff srvr?
'END TYPE

'MACRO DHCP_SERVER_INFO = DHCPDS_SERVER

' // Serie = 12 bytes
'TYPE DHCPDS_SERVERS DWORD
'   Flags       AS DWORD               ' DWORD // not used currently.
'   NumElements AS DWORD               '  DWORD // # of elements in array
'   Servers     AS DHCPDS_SERVER PTR   ' LPDHCPDS_SERVER // array of server info
'END TYPE

'MACRO DHCP_SERVER_INFO_ARRAY = DHCPDS_SERVERS

'//DOC DhcpEnumServers enumerates the list of servers found in the DS.  If the DS
'//DOC is not accessible, it returns an error. The only currently used parameter
'//DOC is the out parameter Servers.  This is a SLOW call.
'DECLARE FUNCTION DhcpEnumServers IMPORT "Dhcpsapi.dll" ALIAS "DhcpEnumServers" ( _
'   BYVAL Flags AS DWORD _                               ' __in  DWORD Flags // must be zero
' , BYVAL IdInfo AS DWORD _                              ' __in  LPVOID IdInfo // must be NULL
' , BYREF Servers AS DHCP_SERVER_INFO_ARRAY _            ' __out LPDHCP_SERVER_INFO_ARRAY *Servers // output servers list
' , BYVAL CallbackFn AS DWORD _                          ' __in  LPVOID CallbackFn // must be NULL
' , BYVAL CallbackData AS DWORD _                        ' __in  LPVOID CallbackData // must be NULL
' ) AS DWORD                                             ' DWORD


DIM EnumDhcpServers AS DHCP_SERVER_INFO_ARRAY
LOCAL nresult, nr AS DWORD
nr=0

nresult = DhcpEnumServers(nr,nr, EnumDhcpServers,nr,nr)

MSGBOX  "nresult " + STR$(nresult)

END FUNCTION


[José Roca]

It must be something like

Code Select Expand


FOR i = 0 TO EnumDhcpServers.NumElements - 1
   ? EnumDhcpServers.@Servers[i].@ServerName
NEXT


[Guy Fournier]

Hi José,

I test many things ... I understand the structure, but I'm sorry I dont understand the pointers. I used your code and I'm not lucky ....

I tried with DhcpEnumSubnetClients it's the same logical but now I see nrusult = 0 and the ClientInfo.NumElements = 9580192 after that general fault with pb10.

Rainy day = bad day ! I continue the work

Thank you for your help

Code Select Expand


#COMPILE EXE
#DIM ALL

#INCLUDE "d:\dns\dhcpsapi.inc"

FUNCTION PBMAIN () AS LONG

'   DECLARE FUNCTION DhcpEnumSubnetClients IMPORT "Dhcpsapi.dll" ALIAS "DhcpEnumSubnetClients" ( _
'   BYREF ServerIpAddress AS WSTRINGZ _                  ' __in DHCP_CONST WCHAR *ServerIpAddress
' , BYVAL SubnetAddress AS DWORD _                       ' __in DHCP_IP_ADDRESS SubnetAddress
' , BYREF ResumeHandle AS DWORD _                        ' __in_out DHCP_RESUME_HANDLE *ResumeHandle
' , BYVAL PreferredMaximum AS DWORD _                    ' __in DWORD PreferredMaximum
' , BYREF ClientInfo AS DHCP_CLIENT_INFO_ARRAY _         ' __out LPDHCP_CLIENT_INFO_ARRAY *ClientInfo
' , BYREF ClientsRead AS DWORD _                         ' __out DWORD *ClientsRead
' , BYREF ClientsTotal AS DWORD _                        ' __out DWORD *ClientsTotal
' ) AS DWORD                                             ' DWORD

LOCAL ServerIpAddress AS STRINGZ * 64
LOCAL SubnetAddress AS DWORD
LOCAL ResumeHandle AS DWORD
LOCAL PreferredMaximum AS DWORD
LOCAL ClientInfo AS DHCP_CLIENT_INFO_ARRAY
LOCAL ClientsRead AS DWORD
LOCAL ClientsTotal AS DWORD
LOCAL nresult  AS DWORD
LOCAL i AS DWORD

SubnetAddress = &H0a349400 '10.52.148.0 vlan
ResumeHandle=0
ClientsRead=0
ClientsTotal=0

nresult=DhcpEnumSubnetClients("10.52.45.125",SubnetAddress,ResumeHandle,65536, ClientInfo,ClientsRead,ClientsTotal)

MSGBOX  "nresult " + STR$(nresult) + ": " + STR$(ClientInfo.NumElements)

FOR i = 0 TO ClientInfo.NumElements  - 1
   MSGBOX [email]ClientInfo.@Clients[i].@ClientName[/i][/email]   
[i]NEXT


END FUNCTION       [/i]