To implement custom protocols, or to customize implementation of well-known protocols, a programmer needs a working knowledge of the basic socket infrastructure.
It is based on Linux based socket programming. If you are comfortable with basics of socket programming and multithreading in c then this article is for you! To revise basics of socket programming, please visit my earlier article. This proxy server application is as follows: Three programs will run at a time in separate Linux terminals, of course.!
One is main server. It acts as a echo server.
One is proxy server. It forwards data from client to main server. And server response back to client Last one is a client. It supports multiple clients. There will be only one main server and one proxy server 4. Proxy server will accept three arguments from command line.
Since proxy is running on a local machine. Its IP address will be No need to mention that in the command line. Client will accept two arguments. These include proxy's IP address and port.
Now you can directly jump to the code. Copy-paste it and run it for further study. For newbies, I'm explaining how programs work in brief. The application flow is as follows: Client will accept proxy details and connect to the specified proxy through socket Proxy server will accept server details and store the details in variables Proxy server also create a socket at the mentioned proxy port and start listening for incoming client connections continuously on that port.
For each successfully accepted client connection, proxy server will create a thread and pass client details client file descriptor and server details ip and port to that newly created thread.
Lets call this thread as client thread. This client thread will create a socket connection and connect to the main server. Now each thread will be responsible for communication between that client and main server.
While main server will accept client connections and create its own thread for each client. Lets call these threads as server threads. This will help main server to differentiate traffic between multiple clients.
Here, main trick is to manage multiple client connections via proxy server. I implemented it using multithreading. Instead of multithreading, you can use a 'select command' which can also serve the same purpose. It is used for synchronous IO multiplexing.
Following link covers the details of it with multi chat client-server application using select command: Codes are modular in multithreading and all accepted client-server connections are independent of each other. When client exits, that particular thread will exit. But the disadvantage of threads is that threads create complexity in the program.
So, Thats all folks! Now you are ready to run your own proxy server application with the help of following code. See the results and modify it as per your requirements.C++:: UDP Socket Library On Linux Jan 29, I'm attempting to write a little UDP socket library in c++ on linux so a user can just create a new instance of a UDPSocket class, specify destination ip and port, and just connect.
UDP sockets. This article describes how to write a simple echo server and client using udp sockets in C on Linux/Unix platform.
|Choosing an API Family||Pipes are common on Linux command lines but do not have a system-wide name. So, any two processes that wish to communicate using a pipe need to be related, either parent and child or, sharing a common parent, who sets up the pipe and passes its file descriptors to individual processes.|
|TCP/IP Socket Programming in C and C++ (Client Server Program) - The Crazy Programmer||Then start the modified client. You should get a reply like this:|
|Friday, December 28, 2012||Examples and practices described in this page don't take advantage of improvements introduced in later releases. What Is a Socket?|
|Calculator using Remote Procedure Calls | Shalikafdo's Blog||How to write a simple RPC Programme?|
|Simple Client Program||A simple client[ edit ] To start with, we'll look at one of the simplest things you can do:|
UDP sockets or Datagram sockets . Develop a client/server based application using UDP to execute the program at remote server. i.e. the client sends the executable file to the server, server executes the file, stores the result in a file and sends back to the client.
client is a personal computer or individual computer while server is a computer that contains information and data to be attheheels.com gets information from server In networking terms a server is.
Write and run a client and server program using C - language in UNIX as per following details: • TCP client program will establish connection and send a text string to the server. Oct 28, · The server program will execute on Linux machine & the client program will run on windows machine throw SSH Client connecting with linux machine.
When the both programs are running if we write something on server it will be seen in client as well as if in client we write something it will be seen in server.