/// <summary>
/// Returns a deduplicated list of all computers in the NetworkNeighborhood
/// </summary>
/// <returns>List of computers in the NetworkNeighborhood</returns>
private async Task <ICollection <IPHostEntry> > GetHostsAsync()
{
if (!_browsers.Any())
{
ServiceRegistration.Get <ILogger>().Error("NeighborhoodBrowserService: No Browsers enabled in NeighborhoodBrowserServiceSettings.xml");
return(new List <IPHostEntry>());
}
var stopWatch = System.Diagnostics.Stopwatch.StartNew();
ICollection <IPHostEntry> result = null;
var tasks = _browsers.Select(browser => browser.GetHostsAsync()).ToList();
try
{
await Task.WhenAll(tasks);
result = Combine(tasks.Select(task => task.Result).ToList());
NeighborhoodBrowserHelper.LogResult(result, GetType().Name, stopWatch.ElapsedMilliseconds);
}
catch (Exception e)
{
ServiceRegistration.Get <ILogger>().Error("NeighborhoodBrowserService: Error collecting neighborhood computers", e);
}
return(result);
}
/// <summary>
/// Asynchronously returns a collection of IPHostEntries of all computers found in the NetworkNeighborhood
/// </summary>
/// <returns></returns>
private async Task<ICollection<IPHostEntry>> DoGetHostsAsync()
{
var stopWatch = Stopwatch.StartNew();
// Enumerate all computers in the NetworkNeighborhood for all Domains / Workgroups
var hosts = new Dictionary<String, Task<IPHostEntry>>();
try
{
using (var root = new DirectoryEntry(PROVIDER_STRING))
{
foreach (DirectoryEntry domain in root.Children)
{
using (domain)
{
foreach (DirectoryEntry computer in domain.Children)
{
using (computer)
{
if (computer.SchemaClassName == COMPUTER_OBJECT)
{
ServiceRegistration.Get<ILogger>().Info("DirectoryEntryNeighborhoodBrowser: Adding '{0}' to hosts list.", computer.Name);
hosts[computer.Name] = Dns.GetHostEntryAsync(computer.Name);
}
}
}
}
}
}
}
catch (Exception e)
{
ServiceRegistration.Get<ILogger>().Error("DirectoryEntryNeighborhoodBrowser: Error while enumerating computers in the NetworkNeighborhood", e);
}
// Wait until an IPHostEntry was found for all computers
try
{
await Task.WhenAll(hosts.Values);
}
catch (System.Net.Sockets.SocketException) { }
catch (Exception e)
{
ServiceRegistration.Get<ILogger>().Error("DirectoryEntryNeighborhoodBrowser: Error while getting IPHostEntries", e);
}
// Assemble the result
var result = new HashSet<IPHostEntry>();
foreach (var kvp in hosts)
{
// If the call to GetHostEntryAsync was successful, we return the retrieved IPHostEntry
// If not, we return a new IPHostEntry object just with its HostName property set.
var host = kvp.Value.IsFaulted ? new IPHostEntry { HostName = kvp.Key } : kvp.Value.Result;
NeighborhoodBrowserHelper.ConvertDnsHostNameToNetBiosName(host);
result.Add(host);
}
NeighborhoodBrowserHelper.LogResult(result, GetType().Name, stopWatch.ElapsedMilliseconds);
return result;
}
/// <summary>
/// Asynchronously returns a collection of IPHostEntries of all computers found in the NetworkNeighborhood
/// </summary>
/// <returns></returns>
private async Task <ICollection <IPHostEntry> > DoGetHostsAsync()
{
var stopWatch = System.Diagnostics.Stopwatch.StartNew();
var networks = NetworkUtils.GetAllLocalIPv4Networks();
ServiceRegistration.Get <ILogger>().Debug("NetbiosNameServiceNeighborhoodBrowser: Found {0} local IPv4 network(s) with IP address(es) {1}", networks.Count, String.Join(" / ", networks.Select(i => i.Address + " (" + i.IPv4Mask + ")")));
networks = RemoveLargeSubnets(networks);
ServiceRegistration.Get <ILogger>().Debug("NetbiosNameServiceNeighborhoodBrowser: {0} local IPv4 network(s) are used: {1}", networks.Count, String.Join(" / ", networks.Select(i => i.Address + " (" + i.IPv4Mask + ")")));
var tasks = new Dictionary <IPAddress, Task <NbNsNodeStatusResponse> >();
using (var client = new NbNsClient())
{
foreach (var target in networks.SelectMany(NetworkUtils.GetAllAddressesInSubnet))
{
if (!tasks.ContainsKey(target))
{
tasks.Add(target, client.SendUnicastNodeStatusRequestAsync(NbNsNodeStatusRequest.WildCardNodeStatusRequest, target));
}
}
await Task.WhenAll(tasks.Values);
// Uncomment the following two lines for extensive logging
// foreach (var kvp in tasks.Where(kvp => kvp.Value.Result != null))
// ServiceRegistration.Get<ILogger>().Debug("NetbiosNameServiceNeighborhoodBrowser: Found {0} ({1})\r\n{2}", kvp.Value.Result.WorkstationName, kvp.Key, kvp.Value.Result);
}
// If the computer has multiple network interfaces, it is found multiple times - once for each network interface.
// Every occurence of the computer then has a different IP address (the one of the respective network interface).
// As result we want this computer only as one IPHostEntry, but IPHostEntry.AddressList should show all IP addresses.
var result = new HashSet <IPHostEntry>();
var responses = tasks.Where(kvp => kvp.Value.Result != null);
foreach (var kvp in responses)
{
var alreadyPresentHost = result.FirstOrDefault(host => host.HostName == kvp.Value.Result.WorkstationName);
if (alreadyPresentHost == null)
{
result.Add(new IPHostEntry {
AddressList = new[] { kvp.Key }, HostName = kvp.Value.Result.WorkstationName
});
}
else
{
if (!alreadyPresentHost.AddressList.Any(address => address.Equals(kvp.Key)))
{
alreadyPresentHost.AddressList = alreadyPresentHost.AddressList.Union(new[] { kvp.Key }).ToArray();
}
}
}
NeighborhoodBrowserHelper.LogResult(result, GetType().Name, stopWatch.ElapsedMilliseconds);
return(result);
}
/// <summary>
/// Asynchronously returns a collection of IPHostEntries of all computers found in the NetworkNeighborhood
/// </summary>
/// <returns></returns>
private async Task <ICollection <IPHostEntry> > DoGetHostsAsync()
{
var stopWatch = Stopwatch.StartNew();
// Enumerate all computers in the NetworkNeighborhood for all Domains / Workgroups
var hosts = new Dictionary <String, Task <IPHostEntry> >();
ICollection <String> hostNames;
// The WNetEnum API requires at least to be impersonated as NetworkService; this is the fallback credential used for
// the root path of NetworkNeighborhoodResourceProvider if no other credentials have been entered.
using (ServiceRegistration.Get <IImpersonationService>().CheckImpersonationFor(NetworkNeighborhoodResourceProvider.RootPath))
hostNames = NetworkResourcesEnumerator.EnumerateResources(ResourceScope.GlobalNet, ResourceType.Disk, ResourceUsage.All, ResourceDisplayType.Server);
// The hostNames returned by the NetworkResourceEnumerator are in the form \\COMPUTERNAME
// We have to remove the leading \\ to be able to pass the hostName to GetHostEntryAsync
foreach (var hostName in hostNames)
{
hosts[hostName.Substring(2)] = Dns.GetHostEntryAsync(hostName.Substring(2));
}
// Wait until an IPHostEntry was found for all computers
try
{
await Task.WhenAll(hosts.Values);
}
catch (Exception e)
{
ServiceRegistration.Get <ILogger>().Error("WNetEnumNeighborhoodBrowser: Error while getting IPHostEntries", e.Message);
}
// Assemble the result
var result = new HashSet <IPHostEntry>();
foreach (var kvp in hosts)
{
// If the call to GetHostEntryAsync was successful, we return the retrieved IPHostEntry
// If not, we return a new IPHostEntry object just with its HostName property set.
var host = kvp.Value.IsFaulted ? new IPHostEntry {
HostName = kvp.Key
} : kvp.Value.Result;
NeighborhoodBrowserHelper.ConvertDnsHostNameToNetBiosName(host);
result.Add(host);
}
NeighborhoodBrowserHelper.LogResult(result, GetType().Name, stopWatch.ElapsedMilliseconds);
return(result);
}
