I want just to add WebSockets to my app that uses WinHTTP in async mode.
When I need a WebSocket I call the following.
Before sending request:
WinHttpSetOption(context->hRequest, WINHTTP_OPTION_UPGRADE_TO_WEB_SOCKET, NULL, 0);
In WINHTTP_CALLBACK_STATUS_SENDREQUEST_COMPLETE:
appContext->pIoRequest->hWebSocketHandle = WinHttpWebSocketCompleteUpgrade(appContext->hRequest, NULL);
WinHttpWebSocketReceive(appContext->pIoRequest->hWebSocketHandle, appContext->pszOutBuffer,RESPONSE_BUFFER_SIZE, NULL, NULL);
all without errors.
Now I see in Fiddler that the server sends some data to my WebSocket but there is no WINHTTP_CALLBACK_STATUS_READ_COMPLETE triggered.
Any ideas why this is? How can I read asynchronously from my WebSocket? Sending data to the WebSocket works well.
Omg! I found how its work!
You MUST call additional WinHttpSetStatusCallback to set WebSocket callback for WebSocketHandle returned in WinHttpWebSocketCompleteUpgrade and this callback MUST differ then that from call WinHttpWebSocketCompleteUpgrade was made!
It is no possible to set a context pointer by WinHttpSetOption with WINHTTP_OPTION_CONTEXT_VALUE flag! Its not work. dwContext In WebSocketCallback has wrong data. Call to WinHttpQueryOption in WebSocketCallback return wrong context data. I think that is a BUG in Windows 8.1. I write my own handler to connect my context with WebSocketHandle.
All of this is NOT documented in MSDN! Most of all, I did not google any info about async winhttp websocket usage... So, I am the first=) I will be very glad if my research will help you!
It seems websockets do not get PING and PONG messages to the callback!
Related
I am trying to do an http api that interact with a Leshan Demo Server.
I was trying to handle the OBSERVE in LWM2M, but I need to handle the notification with http.
I discovered that leshan notify using SSE. So I was trying to implement the sse client in python using requests and sseclient.
This is my code:
response= requests.post(url_request , "format=TLV" , stream= True)
client = sseclient.SSEClient(response)
for event in client.events():
print(json.loads(event.data))
I tried to run my script but it seems like the stream is not opening and it close immediately without waiting for the answer of the server, even if requests by default implement keep_alive for TCP connection under HTTP and the stream is True.
Does someone know why?
Reading the sseclient documentation, the correct way so use SSEClient seems to be :
from sseclient import SSEClient
messages = SSEClient('http://example.com/sse_stream/')
for msg in messages:
do_something_useful(msg)
Reading the answer on Leshan Github, the stream URL for Leshan Server Demo seems to be http://your.leshan.server.org/event?ep=your_device_endpoint_name
So I tried that :
from sseclient import SSEClient
messages = SSEClient('http://localhost:8080/event?ep=my_device')
for msg in messages:
print (msg.event, msg.data)
And it works for me 🎉 ! Getting this kind of results when I observe the temperature instance of Leshan Client Demo :
(u'NOTIFICATION', u'{"ep":"my_device","res":"/3303/0","val":{"id":0,"resources":[{"id":5601,"value":-18.9},{"id":5602,"value":31.2},{"id":5700,"value":-18.4},{"id":5701,"value":"cel"}]}}')
(u'COAPLOG', u'{"timestamp":1592296453808,"incoming":true,"type":"CON","code":"POST","mId":29886,"token":"889372029F81C124","options":"Uri-Path: \\"rd\\", \\"reWfKIgPYD\\"","ep":"my_device"}')
(u'COAPLOG', u'{"timestamp":1592296453809,"incoming":false,"type":"ACK","code":"2.04","mId":29886,"token":"889372029F81C124","ep":"my_device"}')
(u'UPDATED', u'{"registration":{"endpoint":"my_device","registrationId":"reWfKIgPYD","registrationDate":"2020-06-16T10:02:25+02:00","lastUpdate":"2020-06-16T10:34:13+02:00","address":"127.0.0.1:44400","lwM2mVersion":"1.0","lifetime":300,"bindingMode":"U","rootPath":"/","objectLinks":[{"url":"/","attributes":{"rt":"\\"oma.lwm2m\\""}},{"url":"/1/0","attributes":{}},{"url":"/3/0","attributes":{}},{"url":"/6/0","attributes":{}},{"url":"/3303/0","attributes":{}}],"secure":false,"additionalRegistrationAttributes":{}},"update":{"registrationId":"reWfKIgPYD","identity":{"peerAddress":{}},"additionalAttributes":{}}}')
(u'COAPLOG', u'{"timestamp":1592296455150,"incoming":true,"type":"NON","code":"2.05","mId":29887,"token":"3998C5DE2588F835","options":"Content-Format: \\"application/vnd.oma.lwm2m+tlv\\" - Observe: 2979","payload":"Hex:e3164563656ce8164408c03199999999999ae815e108c032e66666666666e815e208403f333333333333","ep":"my_device"}')
If you are interested by notification only, just add a if msg.event == 'NOTIFICATION': block.
I'm having incredible difficulty setting up the Twilio Client in Meteor JS, and would really appreciate any help.
I have extracted the relevant code and error logs below. So far as I can tell, it should be simple. The code is just grabbing an authtoken which I have previously generated, and then trying to set up the device using that authtoken. But it's not working.
'click #initializeDevice'(event) {
var thisAuthToken = Session.get('myAuthToken');
console.log(thisAuthToken); // I have confirmed with Twilio support that these authtokens are correctly generated
const Device = require('twilio-client').Device;
Device.setup(thisAuthToken, { debug: true });
var myStatus = Device.status()
console.log(myStatus); //this is logging "offline"
Device.on('ready',function (device) {
log('Twilio.Device Ready!'); //this is not logging anything
});
},
When that code runs, it generates the following logs:
eyJhbGciDpvdXRnb2luZz9hcHBTaWQ9QVA2NDE2MzJmMzA1ZjJiY2I[Note:I have deleted part of the middle of the logged authtoken for the purpose of this public post]5YmMxOGQyOWVlNGU2ZGM0NjdmMzRiNDVhNCIsImV4cCI6MTU3Nz0ygbJKTx15GgNCWDkm-iUPjn_O1NZU6yovp4vjE
modules.js?hash=69069bec9aeba9503ae3467590cf182be57d9e62:3605 Setting up VSP
modules.js?hash=69069bec9aeba9503ae3467590cf182be57d9e62:3605 WSTransport.open() called...
modules.js?hash=69069bec9aeba9503ae3467590cf182be57d9e62:3605 Attempting to connect...
modules.js?hash=69069bec9aeba9503ae3467590cf182be57d9e62:3605 Closing and cleaning up WebSocket...
modules.js?hash=69069bec9aeba9503ae3467590cf182be57d9e62:3605 No WebSocket to clean up.
modules.js?hash=69069bec9aeba9503ae3467590cf182be57d9e62:3605 Could not connect to endpoint: ws does not work in the browser. Browser clients must use the native WebSocket object
modules.js?hash=69069bec9aeba9503ae3467590cf182be57d9e62:3605 Closing and cleaning up WebSocket...
modules.js?hash=69069bec9aeba9503ae3467590cf182be57d9e62:3605 No WebSocket to clean up.
calltemplate.js:31 offline
I'm doing this all from a local server, tunneled through NGROK. I've also set up the Twilio back end, linked the app, purchased a number, etc.
So far as I can tell, the issue, from the logs, appears to be something to do with the way that Meteor uses WebSockets.
Could not connect to endpoint: ws does not work in the browser. Browser clients must use the native WebSocket object
This is a not a Meteor related problem rather than browser issue.
Make sure your browser supports WebRTC
BTW, Your browser might be supporting it but you'd need to enable it.
I try to implement a websocket client (with libwebsockets in C and it's not an option). As example, i used the test-client.c given with the library.
My websocket-client actualy works fine with the test-server.c . But i experienced some complications to communicate with an nginx server.
As i understand, the handshack doesn't end up well because nginx doesn't know my websocket client's sub-protocol.
Well, it appears, like in test-client.c i'm implementing my own sub-protocol (with its own name, its own callback function).
My questions are :
Is there a way to not use a specific websocket sub-protocol with libwebsockets ?
If not, am i supposed to implement an existing one (client side) like WAMP or something in this list? (I do not want to reinvent the wheel...)
If not, does it exist a "default" websocket subprotocol that i can specify to nginx and in which it could be compatible with my websocket-client ? (I'm only doing some simple send/receive action with my client. Implementing a libwebsockets client seems completly useless if it can only communicate with a libwebsockets server)
Are my questions relevant? If not why ? What am i missing ?
Any help is appreciated.
Thanks!
As discussed with Andy, the libwebsockets designer (https://github.com/warmcat/libwebsockets/issues/834), the simpliest way to make it works is to not named the sub-protocol in the structure defining the websocket sub-protocol client's side :
/* list of supported sub-protocols and callbacks */
static struct lws_protocols ws_protocols[] = {
{ NULL, ws_callback, 0, 128, },
{ NULL, NULL, 0, 0 } /* end */
};
Libwebsockets client doesn't try to negociate with sec-websocket-protocol in the header, the handshake works just fine with nginx.
What is the rationale behind the following exception when trying to Defer the sending of a message on a one-way client:
System.InvalidOperationException "Cannot use ourselves as timeout manager because we're a one-way client"
A one-way client is a Rebus client that is not capable of receiving messages, so it has no input queue.
The way await bus.Defer(...) works, is by sending a message with some special headers to a "timeout manager", which by default is the endpoint that defers the message.
But since a one-way client has no input queue, it has no place to send the deferred message to.
You can make a one-way client defer messages by configuring an external timeout manager like this:
Configure.With(...)
.(...)
.Options(o => o.UseExternalTimeoutManager(anotherQueue))
.Start();
which will then cause the client to send the deferred message to that queue.
Moreover, you would have to manually set the rbs2-defer-recipient header to some other input queue, so that the timeout manager knows where to send the message when it is time to be consumed(*).
I hope that explains it :) please let me know if it is not clear.
*) This is actually not the case with Rebus 4, because bus.Defer uses the normal endpoint mappings to route messages.
If Rebus.AzureServiceBus is used there is more simple (or hacky) way to send delayed messages.
You have to specify 2 headers: rbs2-deferred-until and rbs2-defer-recipient and call Publish method like in the example.
var deferredUntil = DateTimeOffset.UtcNow.AddDays(1);
var headers = new Dictionary<string, string>();
headers.Add(Headers.DeferredUntil, deferredUntil.ToString("O", CultureInfo.InvariantCulture));
headers.Add(Headers.DeferredRecipient, #"Rebus requires this ¯\_(ツ)_/¯");
await bus.Publish(new SomeMessage(), headers);
Note: rbs2-defer-recipient is required by Rebus so any dummy values are okay.
Be careful, it looks like a workaround so it may not work after Rebus.AzureServiceBus update. It works for me in 5.0.1.
In my Meteor application I want to receive text messages through Nexmo. How do I create the callback function? I'm thinking of something like
Meteor.methods
'receive_sms': (values) ->
console.log values
But http://hitchticker.meteor.com/receive_sms doesn't really work of course. I can see my method is working when I do Meteor.call('receive_sms', 'test') in my browser, but the network debugger is not really giving me a lot of useful information. The Meteor docs aren't very helpful either.
How do I access the method from elsewhere?
Iron Router and then server side routes. Something like:
Router.route('/download/:file', function () {
// NodeJS request object
var request = this.request;
// NodeJS response object
var response = this.response;
this.response.end('file download content\n');
}, {where: 'server'});
In order to receive sms from nexmo you should make the callback (incoming url) available over the internet. Nexmo won’t be able to call localhost to send the incoming sms messages.
Here are some resources to tunnel request over the internet to localhost.
https://ngrok.com/
http://localtunnel.me/
https://pagekite.net/