I hope this is quite a simple question.. I've got a compiled .exe program on windows, and I know that it connects to some php resource on some web server and fetch some data. They are just one or two KB, but what I'd like to know is: what's the php resource that it connects to? Is there any program able to trace connections of some other program, on windows?
Thank you very much!
Matteo
Wireshark is a network protocol analyzer. It lets you capture and interactively browse the traffic running on a computer network.
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I am writing a program to transfer files through a lan computers, it's been a while I'm searching for file transferring methods in Delphi. I found UDP is a good solution, but there is a problem: in every example or article I found there was a client program beside a server program, but my program have to send and receive to/from every computer in network, there is no specific server or client, something like p2p, I don't want to make a computer Server and another one Client, what should I do? I searched Indy articles too, it's working in Server/Client mode too (as far as I found).
UDP can work in broadcast mode, which is what you need. But such UDP broadcasts are not routable outside the current network (i.e. they are blocked by routers), so you have to implement something more complex if your project needs to be accessible outside the primary physical network.
Do not reinvent the wheel! If you want to see some working source implementing this concept, see Ares Galaxy:
"Delphi self-organizing p2p network project featuring high scale
capability and fast broadcast-type search system. Client supports
multi-source file transfers, partial file sharing, built-in
audio/video player and decentralized chat rooms".
The source code files are available from SourceForge. You could re-use/adapt the P2P network layer for your needs - but take attention to the license terms of Ares source code, if you use it in your projects.
Have a look at Indy's TIdTrivialFTP and TIdTrivialFTPServer components. TFTP is a UDP-based file transfer protocol.
I want to write a app which will run on different computers and need all of then to communicate with each other like "utorrent" (peer to peer). This app only will send text messages.
How can I do this? I mean sending one message to remote computer on the internet?
I have a website and every app at start can send some information to it and find information of other apps on other computers (with PHP) but I do not know how address one computer through internet and send the data directly to that. I can find the ip address with PHP but it is the ip address of router (ISP).
How a message reaches a computer? I'm wondering about addressing every computer?
My brain really stuck here, I really appreciate any help. Thanks.
In a peer-to-peer network there's no centralized server for transmitting the data from one client to another, in this case the clients must be able to act as both the server and client. This means that either you'll have to be using UPnP like most modern torrent clients, which handles port forwarding in the router, or you'll have to manually forward a port to the computer in the router.
A centralized server (like a torrent tracker) is usually used to make the clients aware of each other's existence and tell them where to connect. This is where your PHP script comes in, though PHP might not offer the most effective way of doing this, assuming you're using it in combination with a webserver to serve the data though the http protocol.
As for actual text communication, you could use the Indy socket library for that. I found this example, basically which shows how to do it: http://www.ciuly.com/delphi/indy/indy-10-client-server-basic-demo/
I've searched this subject in stackoverflow and found out that a telnet library would help, and I found a telnet lib here: C# Telnet Library
but I don't know how I can use a telnet library to open a port in my router. I'm using an AT&T 2wire router. Any hints on how I can do this?
You can't. The 2wire router is an island unto itself, if it decides to block a port nothing external can (or should) be able to change that. You are on the wrong track, and would need to restate your goals in order to get a useful answer.
UPnP and other "Hole Punching" techniques do exist: but you'll be in a world of hurt if you try to reply on them for any widespread deployment.
Perhaps you meant to open a connection to a remote server and then establish two way communication. That is easy... and how other games and tools get the job done.
Technically speaking you should not be able to. You shouldn't have outside programatic access to a router to open a port if it's blocked.
If what you mean is opening a port for communication (that is not blocked) then you can simply create Sockets with the address and port (ex. localhost 7777) to establish inter process communication or simply communication with another server.
As I mentioned in a comment below there are ports that are available for use (in C# this can be easily tested, a quick google search will find you many snippets of code for testing if a port is open). A simple approach is to simply start at port 1024 (I believe this is the correct lower bound for ports that should be used by applications, someone correct me if I'm wrong) and just start counting up until you find a port that is available, if you find you've reached some upper limit you can simply report that a connection cannot be made. I hope this clears up a little more and if I have time I will try to find some code I have for this and edit it in but honestly a quick search can net you similar code for checking ports in C#.
I have a Delphi application that reads/writes to a COM port connected to a large hardware device, so I don't usually have the hardware available during development. That said, the communication protocol is fairly simple, so I can generally do the development and have someone onsite test it, and it usually works. Occasionally I run into a harder problem, though. To solve this, I'd like to setup a virtual COM port where one side of the COM port is my application and the other side is a very simple COM port debug console (similar to the old modem terminal programs), where ASCII commands my app sends are logged onscreen and I can type in some ASCII command to send back to my application to simulate the hardware device. I've been unable to find any tools that provide a virtual/software COM port and a console/terminal to debug with. Does anyone have software suggestions and steps to set something like this up?
The software/virtual COM port and terminal need to support Windows 7 64-bit (or Vista 32 if necessary).
I'm doing something similar with paired virtual COM ports created by
http://com0com.sourceforge.net/
I'm using Advanced Virtual COM Port and I'm quite happy with it. Not free, but works like a charm - even with Win7-x64.
Can't you just insert a redirector at the lowest level of your application which will pop up a console instead of writing data to COM? Should not take long.
I can't vouch for it, but sounds like something like this is what you're looking for. http://www.windows7download.com/win7-free-virtual-serial-ports-emulator/yarqmowu.html
I have used Eterlogic's Virtual Serial Ports Emulator successfully for exactly this on a laptop with no serial ports. It's a bit easier to set up than Com0Com, which I have also used. It's also useful for serial port spying if you need to reverse engineer any communications
The 32-bit version is free, the 64-bit version is currently $25. Try it out on Vista32 to see if it does what you need.
I use Com0Com for this purpose, but I don't know whether it works with anything more recent than Windows XP.
Is it possible to emulate incoming messages using Indy (if it's of any importance: I'm using Indy 10 and Delphi 2009)? I want to be able to create these messages locally and I want Indy to believe that they come from specific clients in the network. All the internal Indy handling (choice of the thread in which the message is received and stuff like that) should be exactly the same as if the message would have arrived over the network.
Any ideas on that? Thanks in advance for any tips.
What you want to do has nothing to do with Indy, as you would need to do this on a much lower level. The easiest way to make Indy believe that messages come from a specific client is to inject properly prepared packets into the network stack. Read up on TCP Packet Injection on Google or Wikipedia. EtterCap is one such tool that allows to inject packets into established connections. However, this is definitely going into gray areas, as some of the tools are illegal in some countries.
Anyway, all of this is IMHO much too complicated. I don't know what exactly you want to do, but a specially prepared client or server is a much better tool to emulate certain behaviour while developing server or client applications. You can run them locally, or if you need to have different IP addresses or subnets you can do a lot with virtual machines.
Indy doesn't have any built-in mechanisms for this but thinking off the top of my head I would recommend building a small test application (or a suite) that runs locally on your development machine and connects to your Indy server application to replay messages.
It should be irrelevant to your Indy server applications if a TCP connection is made either locally or from a remote host as the mechanisms by which a server thread is created and a command processed is identical to both scenarios.
My last gig involved using Indy and all our testing was done with a similar Resender type application that would load local message files and send these to the Indy server app.
HTH and good luck!
One thing you can do would be to create virtual machines to run your test clients, that way they will not be seen as "local machine", and its fairly simple to create a complex network with VMS -- provided you have enough memory and disk space. The other advantage of testing with VM's is you can eliminate the development environment completely when its time to focus on deployment. Amazing how much time that saves alone.
VirtualPC is a free download from Microsoft and works fairly well. VMWare has another option, but costs a little more to get started. For development purposes, I prefer the desktop versions but the server versions also work well. You will still need to have a license to install the virtual OS. MSDN membership is probably the cheapest way to go, and allows you to build test environments for other flavors of the OS.
Indy has abstract stack mechanism for crossplatform support (IDStack.pas) I think u can hack the stack for windows (IdStackWindows.pas). It is a class. U can even consider to derivate it and override some functions to do the hack.