System.DirectoryServices.Protocols LdapConnection should have bindtimeout property. how to timeout on bind currently?

[KamranShahid]

I was looking for Bind Timeout during LDAPConnection and didn't find anything yet. my problem detial is also in
https://stackoverflow.com/questions/70121299/ldapconnection-bind-timeout-in-net-core
there is a workaround in old .net framework as mentioned in https://stackoverflow.com/questions/68385657/ldapconnection-bind-timeout but it can't be applied here.

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Issue Details

---

I was looking for Bind Timeout during LDAPConnection and didn't find anything yet. my problem detial is also in
https://stackoverflow.com/questions/70121299/ldapconnection-bind-timeout-in-net-core
there is a workaround in old .net framework as mentioned in https://stackoverflow.com/questions/68385657/ldapconnection-bind-timeout but it can't be applied here.

Author:	KamranShahid
Assignees:	-
Labels:	area-System.DirectoryServices, untriaged
Milestone:	-

[danmoseley]

Hello, if you're proposing new API then please use this template: https://github.com/dotnet/runtime/issues/new?assignees=&labels=api-suggestion&template=02_api_proposal.yml&title=%5BAPI+Proposal%5D%3A+

[KamranShahid]

Hello, if you're proposing new API then please use this template: https://github.com/dotnet/runtime/issues/new?assignees=&labels=api-suggestion&template=02_api_proposal.yml&title=%5BAPI+Proposal%5D%3A+

Basically first asking for any possible solution currently exist for the problem?

[danmoseley]

Ah I'll let area owners reply

[KamranShahid]

For the time being used following approach to trigger timeout when task not completed within certain time

if (obj.IsBindTimeLimit)
            {
                int timeoutSecond = obj.BindTimeOutInSeconds;
                if (timeoutSecond <= 0)
                {
                    timeoutSecond = 5;
                }
                CancellationToken tscancel = new CancellationToken();
                Task t = Task.Run(() =>
                {
                    var credentials = new NetworkCredential(obj.AdminBindUserName, obj.AdminBindPassword);
                    if (obj.LDAPAddressPort.HasValue && obj.LDAPAddressPort > 0)
                    {
                        connection = new LdapConnection(new LdapDirectoryIdentifier(obj.LDAPAddress, obj.LDAPAddressPort.Value, false, false));
                    }
                    else
                    {
                        connection = new LdapConnection(obj.LDAPAddress);
                    }                  
                    connection.SessionOptions.ProtocolVersion = 3;
                    connection.AuthType = AuthType.Basic;
                    connection.Bind(credentials);
                });
              
                if (!t.Wait(timeoutSecond * 1000, tscancel))
                {                    
                    throw new TimeoutException("The timeout interval elapsed");
                }

            }
            else
            {
                var credentials = new NetworkCredential(obj.AdminBindUserName, obj.AdminBindPassword);
                if (obj.LDAPAddressPort.HasValue && obj.LDAPAddressPort > 0)
                {
                    connection = new LdapConnection(new LdapDirectoryIdentifier(obj.LDAPAddress, obj.LDAPAddressPort.Value, false, false));
                }
                else
                {
                    connection = new LdapConnection(obj.LDAPAddress);
                }               
                connection.SessionOptions.ProtocolVersion = 3;
                connection.AuthType = AuthType.Basic;
                connection.Bind(credentials);
            }

But ideally there should be something provided within the api

[joperezr]

Hello @KamranShahid thanks for posting this issue. You are right, we don't seem to have a way to timeout the Bind operation today. Further more, we also don't have a way to perform the action asynchronously, while the underlying libraries (OpenLdap in Linux and wldap32 in Windows) do support an asynchronous bind. Their async versions of Bind aren't perfect in the sense that they don't offer a callback functionallity, but the way it works is that you call Bind to initiate the bind operation and you get a message id back, which you can then poll using ldap_result() to see if the operation is done. I think we should add an Async Bind overload which uses this, and which also takes in a Cancellation token (which can be configured with a timeout) so that would bring the functionality that you want, with the added benefit of not blocking the current thread. If this sounds good to you, we can turn this issue into an API proposal instead following the template that @danmoseley shared above.

[KamranShahid]

Thanks @joperezr
Implementing new async api will be great.
How about my workaround? is that seems fine for the time being till any new Api is been build

[joperezr]

Doing the operation on a separate thread that you then kill is for sure not an ideal solution, but I understand the lack of many other options. One thing to consider, is that instead of doing all of the time-keeping and waiting yourself, you can just use CancellationTokenSource’s timeout feature so the task gets cancelled automatically for you, you can take a look at more info on how it works here: https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/async/cancel-async-tasks-after-a-period-of-time

[joperezr]

Also, keep in mind that with your code you are not really cancelling the bind operation, all you are doing is waiting for the thread where it is running for some time and if the time passes you carry on in the main thread but the t thread is not being killed, so if this thread is hypothetically hung, then it will keep running. In your particular case you are throwing an exception which I assume you are not catching upstack, which is fine since then the app would crash and the actual bind will stop, but if you do catch this exception upstack, keep in mind the operation is not being cancelled.

[KamranShahid]

Doing the operation on a separate thread that you then kill is for sure not an ideal solution, but I understand the lack of many other options. One thing to consider, is that instead of doing all of the time-keeping and waiting yourself, you can just use CancellationTokenSource’s timeout feature so the task gets cancelled automatically for you, you can take a look at more info on how it works here: https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/async/cancel-async-tasks-after-a-period-of-time

haven't used CancellationTokenSource feature yet. can someone please help me out what to tweak in my code to use this feature.
I will try myself as well