WebSocket ability to force IPv6 or IPv4

[xinbingyiran]

UPDATE: Scoped to WebSocket only as there is no way to achieve that.
HttpClient has a way and HttpWebRequest is legacy API (so no need).

---

I find the sulution for httpclient from issues like this.

var handler = new SocketsHttpHandler{
   ConnectCallback = async (context,token)=>{
      // dns get ipv6 and connect
      return ipv6stream
   }
};
var client = new HttpClient(handler);// HttpClientHandle???

but it can useful for httpclient only,and it replaced httpclienthandle,will lost the diagnosticsHandler yet.

and I view the httpwebrequest and websocket source code, the SocketsHttpHandler is a private member of them only,and i can't get the ConnectCallback for using.

so how can i force ipv6 or ipv4 on httpwebrequest, websocket and httpclient(with diagnosticsHandler )

[ghost]

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Issue Details

---

I find the sulution for httpclient from issues like this.

var handler = new SocketsHttpHandler{
   ConnectCallback = async (context,token)=>{
      // dns get ipv6 and connect
      return ipv6stream
   }
};
var client = new HttpClient(handler);// HttpClientHandle???

but it can useful for httpclient only,and it replaced httpclienthandle,will lost the diagnosticsHandler yet.

and I view the httpwebrequest and websocket source code, the SocketsHttpHandler is a private member of them only,and i can't get the ConnectCallback for using.

so how can i force ipv6 or ipv4 on httpwebrequest, websocket and httpclient(with diagnosticsHandler )

Author:	xinbingyiran
Assignees:	-
Labels:	area-System.Net, untriaged
Milestone:	-

[scalablecory]

There's no way to do this with HttpWebRequest or WebSocket.
The former is obsolete and not being invested in. We could consider an API for WebSocket, though.

Not being able to use DiagnosticsHandler with SocketsHttpHandler is a known wart -- tracking that at #31261

[xinbingyiran]

Except DiagnosticsHandler,for replace the HttpWebRequest,I can use HttpClient via ConnectCallback to implement a ipv6 web request , I'm really looking forward to a similar API for 'WebSocket' as well.

[scalablecory]

Except DiagnosticsHandler,for replace the HttpWebRequest,I can use HttpClient via ConnectCallback to implement a ipv6 web request , I'm really looking forward to a similar API for 'WebSocket' as well.

Actually, you can use WebSocket.CreateFromStream here, so I don't think any new API is needed.

[xinbingyiran]

Except DiagnosticsHandler,for replace the HttpWebRequest,I can use HttpClient via ConnectCallback to implement a ipv6 web request , I'm really looking forward to a similar API for 'WebSocket' as well.

Actually, you can use WebSocket.CreateFromStream here, so I don't think any new API is needed.

If I use WebSocket.CreateFromStream,it means i must copy all code of 'WebSocketHandle.ConnectAsync',and add 'ConnectCallback' to 'SocketsHttpHandler',to completed the websocket protocol upgrade manual,just for use ConnectCallback
only.
does it has a simple implement such as add the 'SocketsHttpHandler' or 'ConnectCallback' member to 'ClientWebSocketOptions'.

[karelz]

Triage: @xinbingyiran how much code is that? Is that inconveniently long code?

[xinbingyiran]

Triage: @xinbingyiran how much code is that? Is that inconveniently long code?

Yes, It's not,but...
At present,if a developer need to switch a option for using ipv4 or ipv6,he must view the source code of runtime, to find the logic of connection(it may be a long time),and then copy all of them to his own code and change it carefully.
Only for using ipv6 or ConnectCallback of SocketsHttpHandler.do you think it's a better way than to offer an option?
And there is a SocketsHttpHandler for using in ClientWebSocketOptions,why not try exposing it or its callback method to the developer?

[wfurt]

In general case, this should not be needed, right @xinbingyiran? If the service is not IPv6 capable, it should not be in DNS in first place. If IPv6 is not available on the client it should fall-back to IPv4. The ConnectCallback was added primarily for use-cases other than this.
While WebSocket may be interesting , HttpWebRequest is viewed as obsolete and it will be official marked as such soon.

[xinbingyiran]

What if I need to connect to a 'WebSocket' server that supports both IPv4 and IPv6(e.g. ws://localhost/) over the IPv4 protocol? Just like I need to make an IPv4 Web request, @wfurt .

Since HTTP is supported, how about WebSocket?

[wfurt]

In that case, both address families should be fully interchangeable, right @xinbingyiran?
I'm not trying to say there is never reason - but most changes are driven by impact and that seems be bigger for HttpClient/SocketsHttpHandler.do as more commonly used.
Even with that, the work is not quite completed and I expect improvements for .NET 6.
WebSocket may see changes when everything is stable and proven to work well if there is broader need.

[xinbingyiran]

Well, hopefully the next version of WebSocket will do that, since it will have to build HTTP first (which can be switched now) after all.

[karelz]

Triage: Issue scoped to just WebSocket. Top post updated.

[antonfirsov]

@xinbingyiran I'm wondering if you can elaborate a bit on your use-case.

In #47583 we are proposing a switch to globally disable IPv6, is this something you would find useful?

[geoffkizer]

At some point we had discussed allowing you to specify and configure the instance of SocketsHttpHandler that is used by the WebSocket. Seems like that would allow you to address this scenario.