private string GetDomainController(string server, string domainDns, DsGetDcNameFlags flags, ref DcLocatorMode mode)
{
string key = BuildDcCacheKey(server, domainDns, flags);
DcLocatorMode mode2 = mode;
try
{
if (flags.HasFlag(DsGetDcNameFlags.DS_FORCE_REDISCOVERY))
{
return(dcCache.AddOrUpdate(
key,
a => this.GetDc(server, domainDns, flags, ref mode2),
(a, b) =>
{
this.logger.LogTrace("New DC requested");
return this.GetDc(server, domainDns, flags, ref mode2);
}));
}
return(dcCache.GetOrAdd(key, k => this.GetDc(server, domainDns, flags, ref mode2)));
}
finally
{
mode = mode2;
}
}
private static extern int DsGetDcName
(
[MarshalAs(UnmanagedType.LPTStr)]
string computerName,
[MarshalAs(UnmanagedType.LPTStr)]
string domainName,
[In] int domainGuid,
[MarshalAs(UnmanagedType.LPTStr)]
string siteName,
[MarshalAs(UnmanagedType.U4)]
DsGetDcNameFlags flags,
out IntPtr pDomainControllerInfo
);
private static extern int DsGetDcName(string computerName, string domainName, IntPtr domainGuid, string siteName, DsGetDcNameFlags flags, out IntPtr domainControllerInfo);
public static extern DWORD DsGetDcName(string computerName,
string domainName,
PGUID domainGuid,
string siteName,
DsGetDcNameFlags flags,
out PDOMAIN_CONTROLLER_INFO dsInfo);
public static extern DWORD DsGetDcName(string computerName,
string domainName,
PGUID domainGuid,
string siteName,
DsGetDcNameFlags flags,
out PDOMAIN_CONTROLLER_INFO dsInfo);
public static extern Win32Error DsGetDcName(string ComputerName, string DomainName, IntPtr DomainGuid,
string SiteName, DsGetDcNameFlags Flags, out SafeNetApiBuffer DomainControllerInfo);
public T FindDcAndExecuteWithRetry <T>(string server, string domain, DsGetDcNameFlags flags, DcLocatorMode mode, Func <string, T> action)
{
int retryCount = 0;
Exception lastException = null;
HashSet <string> attemptedDCs = new HashSet <string>(StringComparer.OrdinalIgnoreCase);
if (domain == null)
{
domain = Domain.GetComputerDomain().Name;
}
DcLocatorMode cachedMode = mode;
string dc = this.GetDomainController(server, domain, flags, ref cachedMode);
while (retryCount < MaxRetry && attemptedDCs.Add(dc))
{
//this.logger.LogTrace("Attempting to execute operation in domain {domain} against DC {dc}", domain, dc);
try
{
return(action.Invoke(dc));
}
catch (COMException ex) when(ex.HResult == -2147016646) // Server is not operational
{
lastException = ex;
}
catch (Win32Exception we) when(we.HResult == -2147467259 || // RPC_NOT_AVAILABLE
we.NativeErrorCode == 0x000020E1 || // ERROR_DS_GCVERIFY_ERROR
we.NativeErrorCode == 0x0000200E || // ERROR_DS_BUSY
we.NativeErrorCode == 0x0000200F || // ERROR_DS_UNAVAILABLE
we.NativeErrorCode == 0x0000203A // ERROR_DS_SERVER_DOWN
)
{
lastException = we;
}
catch (Exception ex) when(ex.InnerException is Win32Exception we &&
(we.HResult == -2147467259 || // RPC_NOT_AVAILABLE
we.NativeErrorCode == 0x000020E1 || // ERROR_DS_GCVERIFY_ERROR
we.NativeErrorCode == 0x0000200E || // ERROR_DS_BUSY
we.NativeErrorCode == 0x0000200F || // ERROR_DS_UNAVAILABLE
we.NativeErrorCode == 0x0000203A // ERROR_DS_SERVER_DOWN
))
{
lastException = ex;
}
this.logger.LogTrace(lastException, "Operation failed in domain {domain} against DC {dc} due to retry-able error", domain, dc);
dc = this.GetDomainController(server, domain, flags | DsGetDcNameFlags.DS_FORCE_REDISCOVERY, ref cachedMode);
retryCount++;
}
dcCache.TryRemove(BuildDcCacheKey(server, domain, flags), out _);
if (lastException != null)
{
throw lastException;
}
else
{
throw new DirectoryException("Unable to execute command against DC");
}
}
public T FindDcAndExecuteWithRetry <T>(string domain, DsGetDcNameFlags flags, Func <string, T> action)
{
return(this.FindDcAndExecuteWithRetry(null, domain, flags, DcLocatorMode.LocalDcLocator, action));
}
public string GetDc(string server, string domainDns, DsGetDcNameFlags flags, ref DcLocatorMode mode)
{
string dc;
if (server != null)
{
bool hadNextClosestSite = flags.HasFlag(DsGetDcNameFlags.DS_TRY_NEXTCLOSEST_SITE);
if (mode.HasFlag(DcLocatorMode.RemoteDcLocator))
{
try
{
flags |= DsGetDcNameFlags.DS_TRY_NEXTCLOSEST_SITE;
this.logger.LogTrace("Remote DCLocator: Finding domain controller for server {server}, domain {domainDns} with flags {flags}", server, domainDns, flags.ToString());
dc = NativeMethods.GetDomainControllerForDnsDomain(server, domainDns, null, flags);
this.logger.LogTrace("Remote DCLocator: Found DC {dc} for server {server} in domain {domainDns}, with flags {flags}", dc, server, domainDns, flags.ToString());
return(dc);
}
catch (DirectoryException dex) //when (dex.InnerException is Win32Exception wex && wex.NativeErrorCode == 1722)
{
mode &= ~DcLocatorMode.RemoteDcLocator;
this.logger.LogWarning(dex, "Could not connect to server {server} to find DC", server);
}
}
if (!hadNextClosestSite)
{
flags &= ~DsGetDcNameFlags.DS_TRY_NEXTCLOSEST_SITE;
}
if (mode.HasFlag(DcLocatorMode.SiteLookup))
{
this.logger.LogTrace("Manual DCLocator: Finding site for server {server}, domain {domainDns} with flags {flags}", server, domainDns, flags.ToString());
string site = this.GetComputerSiteNameManual(domainDns, server);
if (site != null)
{
try
{
this.logger.LogTrace("Manual DCLocator: Attempting to find domain controller for site {site}, in domain {domainDns} with flags {flags}", site, domainDns, flags.ToString());
dc = NativeMethods.GetDomainControllerForDnsDomain(null, domainDns, site, flags);
this.logger.LogTrace("Manual DCLocator: Found DC {dc} for site {site} in domain {domainDns}, with flags {flags}", dc, site, domainDns, flags.ToString());
return(dc);
}
catch (DirectoryException dex) when(dex.InnerException is Win32Exception wex && wex.NativeErrorCode == 1355)
{
mode &= ~DcLocatorMode.SiteLookup;
this.logger.LogWarning(dex, "There are no domain controllers in the site {site}", site);
}
}
else
{
this.logger.LogTrace("Manual DCLocator: No site found for server {server}", server);
}
}
}
this.logger.LogTrace("Local DCLocator: Finding domain controller for domain {domainDns} with flags {flags}", domainDns, flags.ToString());
dc = NativeMethods.GetDomainControllerForDnsDomain(null, domainDns, null, flags);
this.logger.LogTrace("Local DCLocator: Found DC {dc} for domain {domainDns}, with flags {flags}", dc, domainDns, flags.ToString());
return(dc);
}
public string GetDomainController(string server, string domainDns, DsGetDcNameFlags flags)
{
DcLocatorMode mode = DcLocatorMode.LocalDcLocator;
return(this.GetDomainController(null, domainDns, flags, ref mode));
}
private static string BuildDcCacheKey(string server, string domain, DsGetDcNameFlags flags)
{
return($"{server}{domain}{flags}");
}
