[SOLVED] Getting error (87) when calling DhcpRequestParams
lazarus / 34-Windows

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tboege · 2022-10-17 00:22

I am trying to get me head around some relatively simple api-calls.
But I cannot really succeed.
When ever I call the DhcpRequestParams in the routine below, I get
status=87 (=ERROR_INVALID_PARAMETER), which should refer to
AdapterName longer than 256 chars according to
https://learn.microsoft.com/en-us/windows/win32/api/dhcpcsdk/nf-
dhcpcsdk-dhcprequestparams.

Can  you see, what I am doing wrong?


Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.Button1Click(Sender: TObject);var  Adaptername: PWCHAR; 
SendParams, RecdParams: DHCPCAPI_PARAMS_ARRAY;  option15param:
DHCPCAPI_PARAMS;  buffer: pbyte;  size, Status: DWORD; begin  size :=
1024;  GetMem(buffer, size);  Adaptername :=
'{C90A9165-BE89-49AC-B79C-B2F6D5DF7B91}';  option15param.Flags := 0; 
option15param.OptionId := OPTION_DOMAIN_NAME;  option15param.IsVendor
:= False;  option15param.Data := nil;  option15param.nBytesData := 0; 
RecdParams.nParams := 1;  RecdParams.Params := @option15param; 
SendParams.Params := nil;  SendParams.nParams := 0;     Status :=
DhcpRequestParams(DHCPCAPI_REQUEST_SYNCHRONOUS, nil, Adaptername,   
nil, SendParams, RecdParams, buffer, @size, nil); 
Memo1.Lines.Add(StrPas(PChar(buffer)));  Button1.Caption :=
IntToStr(Status); end;

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tboege · 2022-10-17 11:48

I figured out, the code works as expected, when I compile for 32bit
windows - but I only get the status=87 when compiling for 64 bit

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ASerge · 2022-10-19 00:36

Quote from: tboege on October 17, 2022, 02:22:21 amCan  you see, what
I am doing wrong?
Could there be an incorrect adapter name?
I don't use DHCP, but this code is executed without errors (gives, of
course, an empty domain name):
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i uses
Windows, jwadhcpcsdk, jwaiptypes, jwaiphlpapi; function
RetrieveDomaintName(AdapterName: PWideChar): string;var  Buffer:
array[0..1000] of Byte;  DomainNameParams: DHCPCAPI_PARAMS; 
RequestParams: DHCPCAPI_PARAMS_ARRAY;  SendParams:
DHCPCAPI_PARAMS_ARRAY;  Size: DWORD = SizeOf(Buffer);  Status:
DWORD;begin  Result := '';  ZeroMemory(@DomainNameParams,
SizeOf(DomainNameParams));  DomainNameParams.Flags :=
OPTION_DOMAIN_NAME;  ZeroMemory(@SendParams, SizeOf(SendParams)); 
RequestParams.nParams := 1;  RequestParams.Params :=
@DomainNameParams;  Status :=
DhcpRequestParams(DHCPCAPI_REQUEST_SYNCHRONOUS, nil,    AdapterName,
nil, SendParams, RequestParams, @Buffer, @Size, nil);  if Status <> 0
then    RaiseLastOSError(Status);  SetString(Result,
PChar(DomainNameParams.Data),
DomainNameParams.nBytesData);end; procedure
TForm1.Button1Click(Sender: TObject);var  Version: DWORD;  BufSize:
ULONG;  P, Buffer: PIP_ADAPTER_INFO;  AdapterName:
UnicodeString;begin  if DhcpCApiInitialize(Version) <> 0 then   
Exit;  try    BufSize := 0;    if GetAdaptersInfo(nil, BufSize) <>
ERROR_BUFFER_OVERFLOW then      RaiseLastOSError;    GetMem(Buffer,
BufSize);    try      if GetAdaptersInfo(Buffer, BufSize) <> 0 then  
    RaiseLastOSError;      P := Buffer;      repeat        AdapterName
:= P^.AdapterName;       
Memo1.Append(RetrieveDomaintName(Pointer(AdapterName)));        P :=
P^.Next;      until P = nil;    finally      FreeMem(Buffer);    end; 
finally    DhcpCApiCleanup;  end;end;

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tboege · 2022-10-19 19:37

I have tried you code. It seems to work in both 32-bit and 64-bit. I
had to replace line 14
with

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
DomainNameParams.Flags := 0;DomainNameParams.OptionId :=
OPTION_DOMAIN_NAME;   
(That could be the reason, why you didnt get a domain name)

I have compared your solution with my code, and found, that my cod
works, if I replace the uses:
  JwaWindows;
  with
 jwadhcpcsdk;

Thank you, very much - if you have an explanation, why jwaWindows not
works in 64bit, but works in 32bit, but have to be replaced with
jwadhcpcsdk , I would like to know.

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ASerge · 2022-10-19 20:03

Quote from: tboege on October 19, 2022, 09:37:07 pmI had to replace
line 14 with
Thanks for the correction

Quote(That could be the reason, why you didnt get a domain name)
I don't get it because I don't use it. I have static and no domain.

QuoteThank you, very much - if you have an explanation, why jwaWindows
not works in 64bit, but works in 32bit, but have to be replaced with
jwadhcpcsdk , I would like to know.
The jwaWindows unit is a container for all jwa units, including
jwadhcpcsdk. I think the problem is that one of the included units
activates the packing of records, which makes the structure
DHCPCAPI_PARAMS not 32 bytes, but only 24.

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tboege · 2022-10-20 08:39

I think you are rigth. I have checked with SizeOf(DHCPCAPI_PARAMS). I
have also tried to add {$PACKRECORDS  C} before the definition af the
record i jwadhcpcsdk and recompile Jedi.
With that addition, it works even when I use JwaWindows. But since I
don't know, if it gives any sideeffects, I will just stick to
jwadhcpcsdk.

Should this be reported as a bug to the maintainers of Jedi (if there
ara any)?

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PascalDragon · 2022-10-21 14:09

Quote from: tboege on October 20, 2022, 10:39:35 amShould this be
reported as a bug to the maintainers of Jedi (if there ara any)?

It should be reported as a bug on our own bug tracker, because the
Jedi units have been imported from the Jedi project a long time ago
and were modified since then.