ASP.net (MVC) and Winsock - c#

I'm working with asp.net MVC. Now I don't know how to send data form a server (using asp.net ) to another server using (win32 console command line). Plz help me.
P/S: Is there any security hole in this method.

Well generally the case is that most ports today are blocked behind firewalls so setting something like that up with winsock, is outdated. If you are tring to connect two servers there are many options, You could look into the System.Web.WebClient,System.Net.HttpWebRequest,Microsoft's Sync Framework, Rhino queues but heres the run down on the first two.
In short, HttpWebRequest gives you more fine grained control over your
request. WebClient does not. It encapsulates most of the stuff for you.
WebClient is very useful if you want to do specialized, one-off tasks, eg:
download file, do forms post etc.
HttpWebRequest is useful if you want to do more complicated stuff.
The WebClient is especically simplified, we can use it's DownloadData,
DownLoadFile to retreive file/stream from remote webserver. Here are some
tech articles and resources describing using webclient or webrequest:
Hosting WCF services, WebClient
here
and webrequest here.

You have two servers trying to communicate. If you are going to use IP (I am assuming you will since you mentioned Winsock) you must choose between these two protocols:
TCP
UDP
Once you've decided which one to use, you can write a server process (the console application) that listen to a specific port (TCP or UDP port depending on what you've chosen) that will serve your client process (the ASP.NET application).
If you use TCP/IP, you use sockets to communicate. If you use UDP/IP, you will send and receive independent packets.
Here is a TCP/IP client/server code sample in C# you can use. You will wrap and run the client portion of this example is a class you can access within ASP.NET MVC.
Here is a UDP/IP server code sample in C#.
Regarding your question of the security of this approach, the question does not provide enough information to answer it properly. You will need to provide more information.

Related

.Net WebSockets in windows Services

I am trying to use web sockets to allow two Windows services on different machines to pass data back and forth. Almost all the examples or information I have found are about using web sockets for Client/Server Side communication. I am having trouble figuring out how to set this up. I have considered using WebSocketHost as apart of Microsoft.ServiceModel.WebSockets, but then I am unsure how to bind it to a local port and not a URL.
Does any one have any suggestions
Thanks
I am trying to use web sockets to allow two Windows services on different machines to pass data back and forth.
You can open sockets on both machines using WebSockets as you found. The examples mention clients and servers because this is the typical usage, however the API really doesn't care. As long as each side has a listener and a sender they can communicate.
However I would like to mention that this isn't as simple as it sounds because both machines aren't always available. Sometimes one or the other is busy or the network is blocked or something else is going on, or the listener is too busy to respond right away, so you're going to end up needing some sort of queuing on both sides.
If you're doing a process based operation where one side tells the other "I want X" and it's a big operation like producing a document, I've found it much more resilient to build a queue in a database and toss the request in there, then wait for the other side to update the record to say it's done.
If they're smaller, faster requests, MSMQ would be more appropriate if you have it available.
However back to your original question, if you want to use it, any of the client-server examples should work just fine. The API doesn't care.
You can use SignalR Self-Host you really don't want to create your own WebSockets framework since this this will take a long time.
Here is a link on how to start a OWIN server in Windows services.
Hosting WebAPI using OWIN in a windows service
And how to set signalR in self host
Tutorial: SignalR Self-Host
You can accomplish this with Memory Mapped Files.
Inter-Process Communication with Memory-Mapped Files

What is the best way of communicating from web->web api->console app and back again?

I'm starting up a little code project to learn from the process, but I am not sure what's the best way of communicating between the different parts.
First, I have a pure html/js client where the users need to get live updates frequently.
Secondly, I'm considering having a web api application running to provide data.
Thirdly I have a console application running, that needs to communicate with the web api application.
So I'm thinking about using WebSockets all the way from client->web api->console app, but I have trouble making it work. I can make the console app work as a server, but I can't figure out how to make the web api work as a client, so that when it spins up, creates a connection to the console app, and keeps it open for communication, while it delivers data to the clients upon requests.
I tried with different implementations and I have ended up with SignalR, as it seems like that's what people use today :)
Since I have all these problems getting a connection I am wondering if there are better ways of sending data that fulfills my requirements?
If WebSocket (using SignalR) is the way to go, can you provide some links with working examples? I have tried all the top links from Google with no success ^^
Thanks in advance
Your WebAPI project can act as WebSocket server as well. Check this link that uses an IHttpHandler, but you can also do it in a WebAIP's controller how is explained here : Using WebSockets with ASP.NET Web API
The console application should connect as client, using for example ClientWebSocket class.
WebSockets are persistent full duplex connections, so once the client is connected both ends can push information to the other end.

Making two programs talk with each other

My group in the university are working on a project, which includes us making a C# program. We have a vision of making a server side console program that is constantly calculating data and then make a client side program that can fetch the data from our server side program. The client side program will then be able to display the data and the user is able to navigate forth and back around the data. Both of these programs will be run on the same computer solely for exercise purpose.
I am wondering how I can get data from the server side program and be able to display it on the client side program.
If both client and server are always on the same machine, there is no need at all to use WCF or Sockets. You can use named pipes for the interprocess communication.
If you're trying to do a more serious client/server application, I recommend you to try Redis which provides a lot of remote features like pub/sub and caching, so you'll avoid reinventing the wheel.
As mentioned in the comments that sounds like you would like to create a "server" like application which you could do with WCF.
http://tech.pro/tutorial/855/wcf-tutorial-basic-interprocess-communication
There are also some workarounds if you wish to do so, using a Database or use a folder containing Text Files,that would include a folder watcher, which you than read, but they are not that elegant.
You can get data to the client program by configuring it by using web.api self hosting. Here is a great link. The server app can be configured to use the same thing. They can both listen and answer one another.
http://www.c-sharpcorner.com/UploadFile/b1df45/Asp-Net-web-api-self-hosting/
Why don't you give ASP.NET Web API a chance?
You'll be creating a REST API that not only a C# program can talk to (any language/implementation - even another server) can talk to your server as long as the end point is correct (in your case would be your IP address and port number) & of course, you don't need both programs to be on the same computer as well :)

Interfacing with a localhost Windows service

I have a server I've written in C#. I need to interface with it so I can reconfigure things, purge caches, disconnect users, view a run console, etc. I can't shut the server down to do any of these things.
The two available options, interface with the server via a Tcp connection or use the Windows conventions (some WCF?).
Which is one more reliable or a "best practice":
Tcp connection and issue requests (only let admin/maintenance requests come from localhost of course) OR
use WCF to somehow access admin/maintenance methods inside the assembly?
Thanks in advance for the nearly always useful feedback.
EDIT: Can anyone offer any alternatives to WCF? The server itself is literally 65kb. It's tiny. And all I'm trying to do now is issue a few admin/maintenance commands to the server. I'm not trying to be the server, it's already done. I just want to interact with from a local host userland application.
EDIT 2: Problem solve: I'm just using a very very small Tcp client to issue requests to my already built out protocol. It's only a couple hundred lines and no bulky overkillish WCF had to be used. WCF just seems like...too too much. That said I need to learn it anyway (and am right now), thanks for the feedback!
I would definitely recommend using WCF. You define your endpoints and the contract, then using binding you configure how the communication is done (TCP, XML SOAP, Named pipes, message queues...).
This technology is pretty convenient: if you want to move for instance from TCP to HTTP SOAP, then you just update your configuration files and it's done; no code to update. Also it's totally interoperable as you can configure WCF to use HTTP (SOAP messages) and consume your services from any language/platform. You'll also find plenty of tutorials and examples on the web.
Here's a nice article about how to host WCF (TCP communication in the example, but you can use something else by modifying the configuration) within a Windows service
You can host a web service inside windows service. It would be TCP of course but without socket level programming on the client.
You can have then a restful interface on top of it. WCF always seemed too heavy to my liking

How are server side applications created, how is client - server communication done?

I would like to have a client-server application written in .NET which would do following:
server is running Linux
on the server there is SQL database (mySQL) containing document URLs
What we want:
- server side would regularly crawl all URLs and create a full text index for them
- client side would be able to perform a query into this index using GUI
The client application is written in .NET using C#. Besides of searching in documents it will be able to do a lot of other things which are not described here and which are done client-side very well.
We would like to use C# for the server side as well, but we have no experience in this area. How are things like this usually done?
Clarifying question now based on some answers:
The thing which is most unclear to me is how client-server communication is usually handled. Is client and server usually using sockets, caring about details like IP addresses, ports or NAT traversal? Or are there some common frameworks and patters, which would make this transparent, and make client-server messaging or procedure calling easy? Any examples or good starting points for this? Are there some common techniques how to handle the fact a single server is required to server multiple clients at the same time?
To use c# on Linux you will need to use Mono. This is an open source implementation of the CLR specification.
Next you need to decide on how to communicate between server and client, from the lowest level of just opening a TCP/IP socket and sending bits up and down, to .Net remoting, to WCF, to exposing webservices on the server. I do not know how compleat WCF implementation is on mono, also I think you may have issue with binary remoting between mono and MS .Net .
I would suggest RPC style WebServices offer a very good solution. WebServices also have the advantage of alowing clients from other platforms to connect easily.
EDIT
In response to the clarification of the question.
I would suggest using mono/ASP.NET/WebServices on the server, if you wish to use c# on both server and client.
One assumption I have made is that you can do a client pull model, where every message is initiated by the client. Using another approach could allow the server to push events to the client. Given the client has the ability to pole the server regularly I don't consider this much of a draw back but it may be depending on the type of application you are developing.
Mono allow execution of c# (compiled to IL) on a Linux box. Mono ASP.NET allows you to use the standard ASP.NET and integrate into Apache see http://www.mono-project.com/ASP.NET and finally WebServices allow you to communicate robustly in a strongly typed manner between you client and your server.
Using this approach negates most of the issues raised in your clarification and makes them someone else's problem.
Sockets/SSL - is taken care of by standard .Net runtime on the client and Apache on the server.
IPAddress/ports/NAT traversal - Is all taken care of. DNS look up will get the servers IP. Open socket will allow the server to respond through any firewall and NAT setup.
Multiple Clients - Apache is built to handle multiple clients processing at the same time as is ASP.NET, so you should not encounter any problems there.
As many have already mentioned there are a number of thing that you have mentioned which are going to cause you pain. I'm not going to go into those, instead I will answer your original question about communication.
The current popular choice in this kind of communication is web services. These allow you to make remote calls using the HTTP protocol, and encoding the requests and responses in XML. While this method has its critics I have found it incredibly simple to get up and running, and works fine for nearly all applications.
The .NET framework has built in support for web services which can definitely be called by your client. A brief look at the mono website indicates that it has support for web services also, so writing your server in C# and running it under mono should be fine. Googling for "C# Web Service Tutorial" shows many sites which have information about how to get started, here is a random pick from those results:
http://www.codeguru.com/Csharp/Csharp/cs_webservices/tutorials/article.php/c5477
have a look at Grasshopper:
"With Grasshopper, you can use your favorite development environment from Microsoft® to deploy applications on Java-enabled platforms such as Linux"
Or see here
The ideea is to convert your app to Java and then run it on Tomcat or JBoss.
Another approach: use the Mod_AspDotNet module for Apache, as described here.
This Basic Client/Server Chat Application in C# looks like a kind of example which might be a starting point for me. Relevant .NET classes are TcpClient and TcpListener

Categories