Get the domain name of a computer from Windows API - c++

Question

In my application I need to know if the computer is the primary domain controller of a domain, so I need to know the domain of the computer to call NetGetDCName function.
Thanks.
EDIT: The problem is related with the DCOM authentication so I need to know the domain to use the DOMAIN\USERNAME in case of a PDC or COMPUTER\USERNAME if I need to use the local authentication database of the computer.

Answer 1

The NetWkstaGetInfo() function returns either the domain name or the workgroup of the computer, and is therefore not a reliable way to determine if the computer is a member of a domain.
The GetComputerNameEx() function will help, used with the ComputerNameDnsDomain parameter, as shown below. This will return an empty string if the computer is in a workgroup, or the DNS name of the domain:
DWORD bufSize = MAX_PATH;
TCHAR domainNameBuf[ MAX_PATH ];
GetComputerNameEx( ComputerNameDnsDomain, domainNameBuf, &bufSize );

Answer 2

I would consider using NetWkstaGetInfo() and pass the local computer name is that first parameter.
#include <Lmwksta.h>
#include <StrSafe.h>
WCHAR domain_name[256];
WKSTA_INFO_100 info = {0};
if (NERR_Success == NetWkstaGetInfo(L"THIS-COMPUTER", 100, &info) &&
SUCCEEDED(StringCchCopy(domain_name, ARRAYSIZE(domain_name), info.wki100_langroup))) {
// use domain_name here...
}

Answer 3

You can use the NetWkstaGetInfo Function do this.
If you pass in null for the computer name it returns info about the local computer.
It will return a WKSTA_INFO_100 instance, which includes the domain name.

Answer 4

If you just want to know if the machine the code is running is the primary domain controller I think your best option is NetServerGetInfo. If you pass 101 as the level parameter it returns an SERVER_INFO_101 structure. Then look for its sv101_type member:
sv101_type
The type of software the computer is running. This member can be one of the following values.
(...)
SV_TYPE_DOMAIN_CTRL: A primary domain controller.

Answer 5

There is a specific function to determine the join status of a Workstation.
https://learn.microsoft.com/en-gb/windows/desktop/api/lmjoin/nf-lmjoin-netgetjoininformation
THere can be 3 statussus, 'Joined' to a workgroup (The good old Windows 3.0 networking) status == NetSetupWorkgroupName, or joined to a domain status == NetSetupDomainName
or unjoined (standalone) status == NetSetupUnjoined
So if you know this, you can call the respective required functions in a reliable way.

Answer 6

Finally I have used this code. It works in local machine, executed remotely nStatus gives a ACCESS_DENIED error.
NET_API_STATUS nStatus;
TOleString oleServerName=strServerName.c_str();
DWORD dwLevel=101;
LPSERVER_INFO_101 pBufServer=NULL;
LPWKSTA_INFO_100 pBufWksta = NULL;
nStatus=NetServerGetInfo(oleServerName, dwLevel,
(LPBYTE*)&pBufServer);
if(nStatus==NERR_Success &&
(pBufServer->sv101_type & SV_TYPE_DOMAIN_CTRL))
{
dwLevel=100;
nStatus=NetWkstaGetInfo(oleServerName, 100,
(LPBYTE*)&pBufWksta);
if(nStatus==NERR_Success)
{
AnsiString strDomain(pBufWksta->wki100_langroup);
m_pgServerConnection->SetDomain(strDomain);
}
}
Thanks to all :)