I am working on a utility for managing multiple computers in a specified domain (not necessarily the domain the computer the application is running on is a member of) within a specified directory root. The problem I am running into is once I have the collection of computer names from the external AD OU, I am unable to manage based on computer name because of DNS. Is it possible to perform DNS lookup on an external DNS server provided the IP of DNS server and credentials for that domain?
Here is the code that I have for the initialization process (works within the same domain). Really appreciate any input!
private Task InitializeComputers()
{
try
{
Computers.Clear();
object cLock = new object();
PrincipalContext context = new PrincipalContext(ContextType.Domain, CurrentConfiguration.LDAPAddress,
CurrentConfiguration.DirectoryRoot, ContextOptions.Negotiate,
CurrentConfiguration.AdminUser, CurrentConfiguration.AdminPassword);
ComputerPrincipal computer = new ComputerPrincipal(context);
computer.Name = "*";
PrincipalSearcher searcher = new PrincipalSearcher(computer);
PrincipalSearchResult<Principal> result = searcher.FindAll();
Parallel.ForEach(result, (r) =>
{
ComputerPrincipal principal = r as ComputerPrincipal;
DirectoryObject cObject = new DirectoryObject(CurrentConfiguration)
{
Name = principal.Name
};
lock (cLock)
{
Computers.Add(cObject);
}
});
}
... // Catch stuff here
}
private async Task InitializeConnections()
{
Task[] tasks = Computers.Select(x => x.CheckConnectionAsync()).ToArray();
await Task.WhenAll(tasks);
}
// This is where I need to be able to get the IP Address. Thoughts???
public Task CheckConnectionAsync()
{
return Task.Run(() =>
{
try
{
Ping PingCheck = new Ping();
PingReply Reply = PingCheck.Send(Name); // <--- need IP Address instead
if (Reply.Status == IPStatus.Success)
{
IsAvailable = true;
IPHostEntry host = Dns.GetHostEntry(Name); // Does not work for machines on different domain.
IPAddress = host.AddressList.FirstOrDefault().ToString();
}
else
{
IsAvailable = false;
IsWMIActive = false;
}
}
... // catch stuff here ...
});
}
To follow up, the solution that I found is derived from Heijden's DNS Resolver. I wrote a simple DnsManager class with a single static GetIPAddress method for extracting the IP out of an A Record.
public static string GetIPAddress(string name)
{
Resolver resolver = new Resolver();
resolver.DnsServer = ((App)App.Current).CurrentConfiguration.DNSAddress;
resolver.Recursion = true;
resolver.Retries = 3;
resolver.TimeOut = 1;
resolver.TranportType = TransportType.Udp;
Response response = resolver.Query(name, QType.A);
if (response.header.ANCOUNT > 0)
{
return ((AnswerRR)response.Answer[0]).RECORD.ToString();
}
return null;
}
Then, the updated CheckConnectionAsync method is now written like so:
public Task CheckConnectionAsync()
{
return Task.Run(() =>
{
try
{
IPAddress = DnsManager.GetIPAddress(Name + "." + CurrentConfig.DomainName);
... // check availability by IP rather than name...
}
// catch stuff here...
});
}
As soon as you plan to query dedicated server as DNS source, you have to step aside from default libs. I tried this (if remember correctly) once investigating dedicated DNS requests:
http://www.codeproject.com/Articles/12072/C-NET-DNS-query-component
Related
I'm trying to listen for UDP packets from unknown source. But can't bind on the "unspecified adress" (0.0.0.0 or ::)
I've already tried listening on ::1. But from what i tested that only works for local connections that don't pass the network interface.
public async void AwaitDiscoveryReply()
{
try
{
using (var client = new UdpClient(AddressFamily.InterNetworkV6))
{
client.Connect(IPAddress.IPv6Any,4568);
var result = await client.ReceiveAsync();
Debug.WriteLine("Received DR");
var stateProtocol = StateProtocol.FromBytes(result.Buffer);
var robeatsDevice = new RobeatsDevice
{
Id = stateProtocol.DeviceId,
Name = stateProtocol.DeviceName,
EndPoint = client.Client.RemoteEndPoint,
StateProtocol = stateProtocol
};
OnDiscoveryReply(new DeviceDiscoveryEventArgs {RobeatsDevice = robeatsDevice});
}
}
catch (Exception ex)
{
Debug.WriteLine(ex);
}
}
This keeps throwing the exception: The requested address is not valid in its context [::]:4568
UDP sockets are connectionless. "Connect" methods on UDP socket implementations, by convention (don't ask me why) establish default endpoints / filter traffic. If you want to receive traffic from any address, you don't need to "connect" at all. Use the constructor with signature UdpClient(Int32, AddressFamily) and delete the Connect() invocation:
public async void AwaitDiscoveryReply()
{
try
{
using (var client = new UdpClient(4568,AddressFamily.InterNetworkV6))
{
var result = await client.ReceiveAsync();
Debug.WriteLine("Received DR");
var stateProtocol = StateProtocol.FromBytes(result.Buffer);
var robeatsDevice = new RobeatsDevice
{
Id = stateProtocol.DeviceId,
Name = stateProtocol.DeviceName,
EndPoint = client.Client.RemoteEndPoint,
StateProtocol = stateProtocol
};
OnDiscoveryReply(new DeviceDiscoveryEventArgs {RobeatsDevice = robeatsDevice});
}
}
catch (Exception ex)
{
Debug.WriteLine(ex);
}
}
Is it possible to get the logon as account using the ServiceController class? I am using the following code to get the service display names and the service status on a remote machine. I do not see a property indicating what account the service is running under. If not then is there another class that I can use to find out what account a service is running under?
ServiceController[] services = ServiceController.GetServices("MyRemotePC");
foreach (ServiceController service in services)
{
Console.WriteLine(
"The {0} service is currently {1}.",
service.DisplayName,
service. Status
);
}
For each service the following first checks to see if the service is running.
If so, it gets the service's processId and uses ManagementObjectSearch to retrieve the corresponding process object. From there it calls GetOwner(out string user, out string domain) from the underlying Win32_Process object, and outputs the result if the call was successful.
The code below worked locally, however I don't have the access to test this against a remote computer. Even locally I had to run the application as an administrator. for GetOwner to not return an error result of 2 (Access Denied).
var services = ServiceController.GetServices("MyRemotePC");
var getOptions = new ObjectGetOptions(null, TimeSpan.MaxValue, true);
var scope = new ManagementScope(#"\\MyRemotePC\root\cimv2");
foreach (ServiceController service in services)
{
Console.WriteLine($"The {service.DisplayName} service is currently {service.Status}.");
if (service.Status != ServiceControllerStatus.Stopped)
{
var svcObj = new ManagementObject(scope, new ManagementPath($"Win32_Service.Name='{service.ServiceName}'"), getOptions);
var processId = (uint)svcObj["ProcessID"];
var searcher = new ManagementObjectSearcher(scope, new SelectQuery($"SELECT * FROM Win32_Process WHERE ProcessID = '{processId}'"));
var processObj = searcher.Get().Cast<ManagementObject>().First();
var props = processObj.Properties.Cast<PropertyData>().ToDictionary(x => x.Name, x => x.Value);
string[] outArgs = new string[] { string.Empty, string.Empty };
var returnVal = (UInt32)processObj.InvokeMethod("GetOwner", outArgs);
if (returnVal == 0)
{
var userName = outArgs[1] + "\\" + outArgs[0];
Console.WriteLine(userName);
}
}
}
I am creating a C# winform application, in which I want to change the Public IP Address, NOT the IPv4 Address like (Hotspot-Shield, ZenMate, OpenVPN, and others do).
I have checked the following links but didn't find enough help, so I am posting this question:
How can you change Network settings (IP Address, DNS, WINS, Host Name) with code in C#
Changing IP address in C#
I write the same code as in the answer of 1st link and also used the libraries but when I check my IP address through google.com it remains the same. I don't know the socket programming.
Here is my code:
namespace WindowsFormsApplication1
{
class ChangeIP
{
public void SetIP(string ipAddress, string subnetMask, string gateway)
{
using (var networkConfigMng = new ManagementClass("Win32_NetworkAdapterConfiguration"))
{
using (var networkConfigs = networkConfigMng.GetInstances())
{
foreach (var managementObject in networkConfigs.Cast<ManagementObject>().Where(managementObject => (bool)managementObject["IPEnabled"]))
{
using (var newIP = managementObject.GetMethodParameters("EnableStatic"))
{
// Set new IP address and subnet if needed
if ((!String.IsNullOrEmpty(ipAddress)) || (!String.IsNullOrEmpty(subnetMask)))
{
if (!String.IsNullOrEmpty(ipAddress))
{
newIP["IPAddress"] = new[] { ipAddress };
}
if (!String.IsNullOrEmpty(subnetMask))
{
newIP["SubnetMask"] = new[] { subnetMask };
}
managementObject.InvokeMethod("EnableStatic", newIP, null);
}
// Set mew gateway if needed
if (!String.IsNullOrEmpty(gateway))
{
using (var newGateway = managementObject.GetMethodParameters("SetGateways"))
{
newGateway["DefaultIPGateway"] = new[] { gateway };
newGateway["GatewayCostMetric"] = new[] { 1 };
managementObject.InvokeMethod("SetGateways", newGateway, null);
}
}
}
}
}
}
}
/// <summary>
/// Set's the DNS Server of the local machine
/// </summary>
/// <param name="nic">NIC address</param>
/// <param name="dnsServers">Comma seperated list of DNS server addresses</param>
/// <remarks>Requires a reference to the System.Management namespace</remarks>
public void SetNameservers(string nic, string dnsServers)
{
using (var networkConfigMng = new ManagementClass("Win32_NetworkAdapterConfiguration"))
{
using (var networkConfigs = networkConfigMng.GetInstances())
{
foreach (var managementObject in networkConfigs.Cast<ManagementObject>().Where(objMO => (bool)objMO["IPEnabled"] && objMO["Caption"].Equals(nic)))
{
using (var newDNS = managementObject.GetMethodParameters("SetDNSServerSearchOrder"))
{
newDNS["DNSServerSearchOrder"] = dnsServers.Split(',');
managementObject.InvokeMethod("SetDNSServerSearchOrder", newDNS, null);
}
}
}
}
}
}
}
And Here is how I am calling those methods:
{
static string local_ip;
string public_ip;
public static string GetLocalIPAddress() //Method For Getting Local Machine IP
{
var host = Dns.GetHostEntry(Dns.GetHostName());
foreach (var ip in host.AddressList)
{
if (ip.AddressFamily == AddressFamily.InterNetwork)
{
return ip.ToString();
}
}
throw new Exception("Local IP Address Not Found!");
}
// Mehod End
local_ip = GetLocalIPAddress();
ChangeIP ip = new ChangeIP();
ip.SetIP(local_ip, null, null); // Calling Method
var getNIC = NetworkInterface.GetAllNetworkInterfaces();
NetworkInterface[] NI = NetworkInterface.GetAllNetworkInterfaces();
string nic = string.Empty;
string dnsServer = string.Empty;
foreach(var r in getNIC)
{
nic = r.Name;
}
foreach(NetworkInterface ninter in NI)
{
if(ninter.OperationalStatus == OperationalStatus.Up)
{
IPInterfaceProperties ipProperties = ninter.GetIPProperties();
IPAddressCollection dnsAddresses = ipProperties.DnsAddresses;
foreach(IPAddress dnsAdrs in dnsAddresses)
{
dnsServer = dnsAdrs.ToString();
}
}
}
ip.SetNameservers(nic, dnsServer); // Calling Method
public_ip = new WebClient().DownloadString("http://icanhazip.com");
}
How you've described your question is not how the internet (is supposed to) work(s).
Windows doesn't let you write raw IP packets, for this you need to use a TAP/TUN driver. But although you send out packets spoofing the source IP address, the internet between you and the destination won't return the route.
If you're operating behind a block of IP addresses, and only want to spoof another in that block, the return address will get back to your local router, but still won't necessary route back to you.
Unless you use TAP/TUN, there's no other way to steal someone else's Public IP address, excluding other network security vulnerability exploitations which are beyond the scope of this forum.
And even with TAP/TUN you're very limited in what you can achieve over spoofed IP packets in one direction. In fact, ISPs may filter out spoofed IP addresses.
I'm current looking at Thrift to use as a RPC framework for our apps (mostly written in C# and Silverlight). I've come as far as implementing a service and consuming it from a C# console app (using a socket as transport).
For the C# server side code my code looked like: (basically copying the tutorials included with the source code)
MyServiceHandler handler = new MyServiceHandler();
MyService.Processor processor = new MyService.Processor(handler);
TServerTransport serverTransport = new TServerSocket(9090);
TServer server = new TSimpleServer(processor, serverTransport);
server.Serve();
For the client side code it looked like:
TTransport transport = new TSocket("localhost", 9090);
TProtocol protocol = new TBinaryProtocol(transport);
MyService.Client client = new MyService.Client(protocol);
transport.Open();
client.SomeServiceCall();
However, we will be consuming the service from a Silverlight client, and unfortunately there is no support for sockets in Silverlight for Thrift. I assume I'm forced to use HTTP communication between the client and service, using Thrift's C# THttpClient and THttpHandler classes? I could not find any examples of how to do this out there, can anyone point me in the right direction? Some example server and client side code would be appreciated.
It seems that this issue was already addressed by this guy. According to this JIRA, the fix is available in Thrift 0.9. You can either try this snapshot (note that, as it's not a final release, it might not be stable) or you can apply this patch to the 0.8 release.
I believe by now you would have understood, there is no direct way of communicating from Silverlight to the Cassandra database either using Thrift or any other clients.
I have one simple option related to this. Write a Silverlight enabled web service and consume it from the client.
For example, on the server side you can have a web service which does insert/update/read etc., like this. I just managed to pull out some code which we use for our project. Hope this helps.
using Apache.Cassandra;
using Thrift.Protocol;
using Thrift.Transport;
namespace CassandraWebLibrary
{
public class MyDb
{
String _host;
int _port;
String _keyspace;
bool _isConnected;
TTransport _transport = null;
Apache.Cassandra.Cassandra.Client _client = null;
String columnFamily = "ColumnFamilyName";
public VazhikaattiDB(String host, int port, String keyspace)
{
_host = host;
_port = port;
_keyspace = keyspace;
_isConnected = false;
}
public bool Connect()
{
try
{
_transport = new TFramedTransport(new TSocket(_host, _port));
TProtocol protocol = new TBinaryProtocol(_transport);
_client = new Apache.Cassandra.Cassandra.Client(protocol);
_transport.Open();
_client.set_keyspace(_keyspace);
_isConnected = true;
}
catch (Exception ex)
{
log.Error(ex.ToString());
}
return _isConnected;
}
public bool Close()
{
if (_transport.IsOpen)
_transport.Close();
_isConnected = false;
return true;
}
public bool InsertData(Send your data as parameters here)
{
try
{
List<Column> list = new List<Column>();
string strKey = keyvalue;
#region Inserting into Coulmn family
List<Byte> valbytes = new List<byte>(BitConverter.GetBytes(value)); //You might have to pad this with more bytes to make it length of 8 bytes
Column doublecolumn1 = new Column()
{
Name = Encoding.UTF8.GetBytes("column1"),
Timestamp = timestampvalue,
Value = valbytes.ToArray()
};
list.Add(doublecolumn1);
Column stringcolumn2 = new Column()
{
Name = Encoding.UTF8.GetBytes("column2"),
Timestamp = timestampvalue,
Value = Encoding.UTF8.GetBytes("StringValue")
};
list.Add(stringcolumn2);
Column timecolumn3 = new Column()
{
Name = Encoding.UTF8.GetBytes("column3"),
Timestamp = timestampvalue,
Value = BitConverter.GetBytes(DateTime.Now.Ticks)
};
list.Add(timecolumn3);
#endregion
ColumnParent columnParent = new ColumnParent();
columnParent.Column_family = columnFamily;
Byte[] key = Encoding.UTF8.GetBytes(strKey);
foreach (Column column in list)
{
try
{
_client.insert(key, columnParent, column, ConsistencyLevel.QUORUM);
}
catch (Exception e)
{
log.Error(e.ToString());
}
}
return true;
}
catch (Exception ex)
{
log.Error(ex.ToString());
return false;
}
}
public List<YourReturnObject> GetData(parameters)
{
try
{
ColumnParent columnParent = new ColumnParent();
columnParent.Column_family = columnFamily;
DateTime curdate = startdate;
IndexExpression indExprsecondkey = new IndexExpression();
indExprsecondkey.Column_name = Encoding.UTF8.GetBytes("column");
indExprsecondkey.Op = IndexOperator.EQ;
List<Byte> valbytes = PadLeftBytes((int)yourid, 8);
indExprsecondkey.Value = valbytes.ToArray();
indExprList.Add(indExprsecondkey);
IndexClause indClause = new IndexClause()
{
Expressions = indExprList,
Count = 1000,
Start_key = Encoding.UTF8.GetBytes("")
};
SlicePredicate slice = new SlicePredicate()
{
Slice_range = new SliceRange()
{
//Start and Finish cannot be null
Start = new byte[0],
Finish = new byte[0],
Count = 1000,
Reversed = false
}
};
List<KeySlice> keyslices = _client.get_indexed_slices(columnParent, indClause, slice, ConsistencyLevel.ONE);
foreach (KeySlice ks in keyslices)
{
String stringcolumnvalue = Encoding.UTF8.GetString(cl.Column.Value);
double doublevalue= (Double)BitConverter.ToDouble(cl.Column.Value);
long timeticks = BitConverter.ToInt64(cl.Column.Value, 0);
DateTime dtcolumntime = new DateTime(timeticks);
}
}
catch (Exception ex)
{
log.Error(ex.ToString());
}
return yourdatalist;
}
}
}
Now the above class can be used by your webservice, which in turn will be used by Silverlight. Btw, you'll have to take care of other silverlight issues like size of data to be downloaded from server/webservice etc.,
FYI, our client service of Cassandra runs on port 9160..
I spend more than a day to find out that the Principal object is using way more bandwidth than the using the DirectoryServices. The scenario is like this. I have a group with ~3000 computer objects in it. To check if a computer is in this group I retrieved the GroupPrincipal and searched for the ComputerPrincipal.
Boolean _retVal = false;
PrincipalContext _principalContext = null;
using (_principalContext = new PrincipalContext(ContextType.Domain, domainController, srv_user, srv_password)) {
ComputerPrincipal _computer = ComputerPrincipal.FindByIdentity(_principalContext, accountName);
GroupPrincipal _grp = GroupPrincipal.FindByIdentity(_principalContext, groupName);
if (_computer != null && _grp != null) {
// get the members
PrincipalSearchResult<Principal> _allGrps = _grp.GetMembers(false);
if (_allGrps.Contains(_computer)) {
_retVal = true;
}
else {
_retVal = false;
}
}
}
return _retVal;
Actually very nice interface but this creates around 12MB traffic per request. If you're domain controller is in the LAN this is no issue. If you access the domain controller using the WAN it kills your connection/application.
After I noticed this I re-implemented the same functionality using DirectoryServices
Boolean _retVal = false;
DirectoryContext _ctx = null;
try {
_ctx = new DirectoryContext(DirectoryContextType.DirectoryServer, domainController, srv_user, srv_password);
} catch (Exception ex) {
// do something useful
}
if (_ctx != null) {
try {
using (DomainController _dc = DomainController.GetDomainController(_ctx)) {
using (DirectorySearcher _search = _dc.GetDirectorySearcher()) {
String _groupToSearchFor = String.Format("CN={0},", groupName);
_search.PropertiesToLoad.Clear();
_search.PropertiesToLoad.Add("memberOf");
_search.Filter = String.Format("(&(objectCategory=computer)(name={0}))", accountName); ;
SearchResult _one = null;
_one = _search.FindOne();
if (_one != null) {
int _count = _one.Properties["memberOf"].Count;
for (int i = 0; i < _count; i++) {
string _m = (_one.Properties["memberOf"][i] as string);
if (_m.Contains(groupName)) { _retVal = true; }
}
}
}
}
} catch (Exception ex) {
// do something useful
}
}
return _retVal;
This implementation will use around 12K of network traffic. Which is maybe not as nice but saves a lot of bandwith.
My questions is now if somebody has an idea what the AccountManagement object is doing that it uses so much bandwith?
THANKS!
I would guess including the following lines will do a lot to save bandwidth:
_search.PropertiesToLoad.Clear();
_search.PropertiesToLoad.Add("memberOf");
_search.Filter = String.Format("(&(objectCategory=computer)(name={0}))", accountName);
The first two are telling the DirectorySearcher to only load a single property instead of who knows how many, of arbitrary size.
The second is passing a filter into the DirectorySearcher, which I guess is probably processed server side, further limiting the size of your result set.