for an installation with multiple mobile phones and computers, i need to implement a socketserver which handles communication between the devices.
For example: Phone 1 wants to make computer 3 play a sound.
When the computer is done playing that sound it sends a message to the phone.
Now in the server i need to make sure that the connection payloads get delivered to the correct recipient.
For now i have an array with all the socket references in it.
When a phone sends the message to the computer the server looks up the socket corresponding to the recipient of the message by comparing the IPs of the message target and the sockets stored in the array to find the correct recipient.
var target_ip:String="192.168.2.25"
var payload:String="hello!"
for each (var sock:Socket in _clientSockets){
if(sock.localAddress==target_ip){
sock.writeUTFBytes(payload);
sock.flush();
break
}
}
Is there a more elegant version to do this?
Should I maybe store the sockets in a dictionary or similar?
Thanks for all tips!
Related
I've got a Windows Store app that's a WinRT Phone/Desktop app (i.e. not a UWP app), targeting Windows 8.1 and up.
It's been on the store for several years now, but recently it stopped being able to connect with various web APIs and websites (YouTube, as well as my own site) using HTTPS.
I have a WPF version of this app as well, and this happened on that app recently as well, and to fix it I used System.Net.ServicePointManager. Unfortunately, in my WinRT environment, System.Net doesn't include ServicePointManager. In my WPF app, I did this, and it worked just fine:
ServicePointManager.ServerCertificateValidationCallback = delegate
{
Debug.WriteLine("returning true (the ssl is valid)");
return true;
};
// our server is using TLS 1.2
ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
In doing some research around the internet, it seems that .NET 4.6 should include ServicePointManager, but I don't see any way to change (or even see) my version of .NET in the WinRT development environment.
I looked some more and found that a StreamSocket could be used to connect with TLS1.2... but that seems primarily designed to enable bluetooth communications, or communications to a web endpoint, but only by hostname... which is insufficient for me. I need to connect to an actual website, not just the base-level domain.
Trying this, I did the following:
StreamSocket socket = new StreamSocket();
string serverServiceName = "https";
socket.Control.KeepAlive = false;
url = "inadaydevelopment.com";
HostName serverHost = new HostName(url);
await socket.ConnectAsync(serverHost, serverServiceName, SocketProtectionLevel.Tls12);
text = await ReadDataFromSocket(socket);
I can include the code for ReadDataFromSocket() if necessary, but it seems to work, reading the data from the socket as expected when I point it at https://google.com. However, I can't seem to figure out how to point the socket at anything useful. The homepage of inadaydevelopment.com isn't what I want; I'm looking to consume a web API hosted on that server, but can't seem to find a way to do that.
Since the first parameter to the ConnectAsync() method is just HostName, the second parameter (remoteServiceName) must be the way to connect to the actual API or webpage I'm trying to connect to. According to the docs, that is The service name or TCP port number of the remote network destination... I haven't seen any example values for this parameter other than https and various numeric values, neither of which is going to get me to the API endpoint or webpage I'm trying to connect to.
So, with that super-long preamble out of the way, my question boils down to this:
Is there a way for me to use System.Net.ServicePointManager in my WinRT app like I do in my WPF app? If so, how?
If not, how can I use StreamSocket to connect to the exact web service or webpage I want to connect to, rather than just the top-level host?
If that's not possible, by what other means can I consume web content using TLS1.2?
Thanks in advance for any help or advice.
Use Windows.Web.Http API instead of System.Net.Http API.
System.Net.Http does not support TLS1.2 but Windows.Web.Http does in WinRT apps.
I have a Line-of-Business (LoB) Windows 8.1 Store application I developed for a client. The client side-loads it on several Windows 10 tablets. They use it in an environment where WiFi is spotty at best and they would like to get some sort of notification inside the app, regardless of what page they are on, notification that will let them know that they've lost connectivity to the network. I have created a method on my Web API that is not hitting the repository (database). Instead, it quickly returns some static information regarding my Web API, such as version, date and time of the invocation and some trademark stuff that I'm required to return. I thought of calling this method at precise intervals of time and when there's no response, assume that the Web API connectivity is lost. In my main page, the first one displayed when the application is started, I have the following stuff in the constructor of my view model:
_webApiStatusTimer = new DispatcherTimer();
_webApiStatusTimer.Tick += OnCheckWebApiStatusEvent;
_webApiStatusTimer.Interval = new TimeSpan(0, 0, 30);
_webApiStatusTimer.Start();
Then, the event handler is implemented like this:
private async void OnCheckWebApiStatusEvent(object sender, object e)
{
// stop the timer
_webApiStatusTimer.Stop();
// refresh the search
var webApiInfo = await _webApiClient.GetWebApiInfo();
// add all returned records in the list
if (webApiInfo == null)
{
var messageDialog = new MessageDialog(#"The application has lost connection with the back-end Web API!");
await messageDialog.ShowAsync();
// restart the timer
_webApiStatusTimer.Start();
}
}
When the Web API connection is lost, I get a nice popup message that informs me that the Web API is no longer available. The problem I have is that after a while, especially if I navigate away from the first page but not necessary, I get an UnauthorizedAccessException in my application.
I use the DispatcherTimer since my understanding is that this is compatible with
UI threads, but obviously, I still do something wrong. Anyone cares to set me on the right path?
Also, if you did something similar and found a much better approach, I'd love to hear about your solution.
Thanks in advance,
Eddie
First, If you are using Windows Store Apps, then you could possibly use a Background task to check poll for the status of the web api instead of putting this responsibility on your view model, its not the viewmodels concern
Second, if you are connecting from your Windows store app to your API then one successful authentication/ authorization for the first time, how and where do you store the token (assuming you are using token authentication). If you are (and ideally you should), is there a timer that you start which is set to the token expiration time? Is your local storage getting flushed somehow and loosing the aurthorization data?
Need more information.
I'm curious if it's possible for me to write programs that can control an Apple TV, specifically an Apple TV 4th gen running tvOS 9.1.1, like Apple's Remote app for iOS can. I'd like to send it commands for navigating in the four cardinal directions, selecting an item on the screen, going up the navigation stack -- essentially what Apple's Remote app can do.
Has anyone done any work reverse engineering the protocol it uses? Cursory Googling only has so far yielded out of date results about earlier generation Apple TVs and the DAAP protocol which looks like something different than what I want.
I captured the traffic on my iPhone using tcpdump and analyzed it with WireShark. The Remote app asks the Apple TV with normal HTTP requests on port 3689.
The workflow of the app consists in four HTTP requests:
/server-info for getting infos about the Apple TV. It responds with a Apple proprietary DAAP response (Digital Audio Access Protocol) providing some tags about the device, like the display name.
/login is performed during connection, when the app displays the "Connecting to Apple TV..." message. It responds with a DAAP about the login status.
Here's the bottleneck. /home-share-verify validates the connection between the app and the Apple TV. This call needs a Client-DAAP-Validation header with a long unknown string value. According to Wikipedia, this seems to be like an hash generated by a certificate exchange between verified sources that was introduced in iTunes 7.0+ and never reverse engineered.
/ctrl-int/1/{controlpromptupdate|controlpromptentry|playstatusupdate} seems to be the calls made for the input buttons.
Some other minor calls are fired in between (like a Bonjour service update or a /databases call).
Here and here you can find more infos. Hope this helps for getting an overview of how this simple (but protected) app works.
i wanted to tell alexa to trigger appletv and that would wake my appletv up and via HDMI & CEC turn my tv on,
in order to do that:
from your mac\linux\windows simply run:
curl -XPOST -d 'cmcc\x00\x00\x00\x01\x30cmbe\x00\x00\x00\x04menu' 'http://10.1.1.56:3689/ctrl-int/1/controlpromptentry?prompt-id=144&session-id=1'
the abstract command is:
curl -XPOST -d 'cmcc\x00\x00\x00\x01\x30cmbe\x00\x00\x00\x04menu' 'http://{APPLETV_IP}:3689/ctrl-int/1/controlpromptentry?prompt-id={CONTROL_PAIR_ID}&session-id={CONTROL_SESSION_ID}'
i extracted the CONTROL_PAIR_ID and CONTROL_SESSION_ID by setting my iphone wifi http proxy settings to my mac with fiddler on it and activated the old appletv remote app and that displayed the requests the app is executing
if you don't know how to set iphone to work with fiddler you can find it here:
http://docs.telerik.com/fiddler/Configure-Fiddler/Tasks/ConfigureForiOS
I did manage to control my Apple TV (currently running tvOS 9.2) from a python script. It turns out that you don't need to use Home Sharing to have a remote app control the Apple TV. I don't know if the following method will work if Home Sharing is enabled, but with it disabled on the Apple TV, the iOS Remote app has the option to manually add a device. (This may require removing all of the devices it is already paired with, since that was unfortunately necessary for me to get it to display the 'Add a device' button.) Once I had paired my iPhone to the Apple TV, I recorded some of its requests, copied the pairing GUID, and then constructed some of my own requests.
The only three requests necessary to make are:
/login?pairing-guid=< your pairing guid here >&hasFP=1
Logs into the Apple TV. The last four bytes of the response's is a session id, encoded as a big-endian four byte integer.
/logout?session-id=< your session id here >
Logs out. Not strictly necessary, as I found that logging in simply gets you a new session id, but probably not a bad idea to do things the way it expects.
/ctrl-int/1/controlpromptentry?prompt-id=114&session-id=< your session id here >
Send user input to the Apple TV. The data is one of several buffers that input a command, or possible a moving touch. For movement in the cardinal directions, sending several of these requests to simulate a moving touch is necessary.
I have a python script demonstrating how to do this here:
http://pastebin.com/mDHc353A
Utilizes the requests library: http://docs.python-requests.org/en/master/
Also special thanks to Adam Miskiewicz / github user skevy, since I made use of this file in his atlas-backend repo that conveniently had the right buffers to send for movement: https://github.com/skevy/atlas-backend/blob/master/atlas/services/appletv.coffee
For any people still checking out this question, I recommend checking out pyatv if they want to control their Apple TV through a python or command line interface.
Minimum To Achieve:- Send nearly or more than 1 mb/second to other websocket clients.
Questions:--
Is it possible video streaming with SuperWebSocket?
What options/features of SuperWebSocket can be used like Asynch
mode/JsonCommands/CustomSession/etc to achieve fastest data
transfer?
How to sequence a big data sent in chunks but if received without any order at client or server side? Is there anything built in to sequence these chunks or I have to manually send sequence nos in message itself?
What I have tried:--
Multiple secure sessions with same port and different paths in javascript code
ws = new WebSocket(wss://localhost:8089/1/1)
ws = new WebSocket(wss://localhost:8089/2/2)
ws = new WebSocket(wss://localhost:8089/3/3)
with above sessions I send large data in chunks but it's not receiving in expected order at server/client side and also after successfully sending large chunk (size=55000kb) that session closes automatically!
I am looking into sample projects of SuperWebSocket but not sure where to go! I am open to try any option inside SuperWebsocket. Thanks
1) I am not sure it does, but if it provides an API to send Byte[], it may be enough.
2) No idea about this one, the documentation may explain it.
3) What do you mean without order? WebSockets is TCP based, so data segments sent in the same connection will arrive in the same order they were sent.
4) Why would you open different connections to the same site? There is also probably limitations about the connections that you can open to the same host. One should be OK, open several is not going to increment your bandwidth, only will increment your problems.
I develop a WebSocket server component that handles messages as Stream derived objects and has an acceptable performance so far, you may like to give it a try.
I'm looking at writing an app with Adobe AIR, but I wanted to figure out if this is feasible with the platform first. (Mostly new to Flash and AIR)
What I would like to do is know ahead of time what local port a URLRequest will be using. If possible, I would like to hold a connection open even and keep using the same socket.
What I'm basically trying to accomplish is doing some NAT-Traversal and port negotiation ahead of time. Once I have both the client and the server negotiated, I'd like them to connect and basically use HTTP in a peer-to-peer way to stream media, like this sample:
var s = new air.Sound();
var url = "http://www.example.com/sounds/bigSound.mp3";
var req = new air.URLRequest(url);
var context = new air.SoundLoaderContext(8000, true);
s.load(req, context);
s.play();
The problem is that I don't see this happening unless I can get some information from AIR on what ports it's planning to use. I would be OK with creating my own Socket connections to the server and using them, but I would need a way to leverage the Sound framework to stream in the same way from a socket.
Ideas? Thoughts? Thanks!
Even if you managed to guess which port AIR is going to use on your device, it is not going to be very helpful, since there is a reasonably high probability that your NAT will translate it to another value IF your AIR device has a private IP address.
This issue does not happen if your AIR server has a public IP address. Most often, you can configure the server's NAT/Router to forward traffic as is. A port scan from the WAN will quickly tell you which port is used.
If you want to 'hijack' an outbound connection created by AIR itself, then you might try to have it contact a special server peer you have implemented which will forward traffic from and to it. Not simple, but possible. Basically you would collect holes punched in the NAT by the server.