I want to make a very simple c++ instant messenger for lan networks and internet (direct IP connect). I know little about sockets. I searched the internet, but nothing really helped. I would someone to suggest a howto/tutorial/guide. I just want to send and receive messages (in a console window, I'll create the gui later). I want it to be for both Linux and Windows. Thanks in advance!
Checkout Boost.Asio. It's portable, and it's also got an example that implements a simple chat.
check out Boost.ASIO
There's some source code here for a C/S chat application that you could probably use to get started.
Mas.
Example Code
Use boost, cross platform, under the link, straight forward example for client-server chat.
Related
I am implementing a messaging system using C++ and Qt. After much thought, I have determined that multicasting or a multicast-style technique will work best to solve my problem. However, I have learned about UDP's unreliability and believe it to be unacceptable.
My requirements are as follows:
Messages are to be sent in a binary serialized form.
From any given node on the network, I must be able to send messages to the other nodes.
Message delivery must be insured.
I have heard of OpenPGM and NORM as alternatives for UDP. If anyone has experience with either of these, could you please share?
I am also open to the possibility of implementing "reliable" multicast by myself, in the application layer, but I would prefer not to if there is a library that already implements this.
I am using C++ and Qt, therefore .NET or Java-based solutions are not acceptable unless they are open-source and I may port them to C++.
Thank you very much.
EDIT 20120816T1853 MDT: An additional question: would either PGM or NORM have to be implemented at the hardware/IP level? Or can they be overlayed on top of existing protocols?
We have implemented our own reliable multicast protocol over UDP called RSP, since we needed something cross-platform and at the time couldn't find a good solution between Linux and Windows. The Windows PGM implementation disconnects slow clients which leave the send window, whereas our implementation throttles the sender similar to TCP. Afaik OpenPGM can be configured to do the same.
The open source NORM at http://cs.itd.nrl.navy.mil/work/norm can be built as a library and has C++ API with Python and Java language bindings. If you ping the developer (me) via the mailing list, I can help get you started.
There is a large RFC division of reliable multicast protocols, and many implementations out there. It's a long time since I looked at this but there are TRAM, LRMP, ...
I'm not looking to use something big like QT or wxWidgets' APIs. I just want simple sockets that will work on Android, iOS, Windows, Mac, Linux.
I'm making an event driven card game so TCP would be best.
Essentially, I just want to connect and authenticate clients. After that I just need to be able to send them messages. I was going to use reliable UDP but TCP seems more appropriate.
If anyone also has basic tutorials for something like a tcp chat application I'd appreciate it.
Thanks
I just want to be able to use, send(), recv, etc without worrying about WINSOCK or POSIX,
Perhaps try BOOST Asio
http://www.boost.org/doc/libs/1_49_0/doc/html/boost_asio.html
Is that light weight enough?
I've made a really simple, lightweight wrapper around the BSD Sockets API. It does TCP/IP communication only, using a server and a client (a server can optionally accept multiple client connections).
You can find it here: (don't mind the Objective-C classes, use tcpconnect.h and tcpconnect.c only): http://github.com/H2CO3/TCPHelper
Perharps Boost.Asio (http://boost.org) or this one http://libunicomm.org based on Asio could be useful for you.
My main goal is to create an advanced program for manipulating the packets that route within my network via the router. Let my program have total control over the router. Set the download/upload speeds to my inputs, apply the effect to certain devices within in my network. Block upload or download traffic. Set second delay for either the upload or download speed. Specify % of loss packets, and the list goes on.
The problem is that I don't know where to start. I know most languages at the very most basic level. I'd like to create this program in either C, C++ or C# but I don't know yet. What else do I need to know before creating this program? Winsock or something? Winpcap APIs?
This goal is my motivation to learn programming to the extreme, and I'm really looking forward to it.
Thanks in advance!
Hmmm I guess you would want to look at pcap(?):
pcap
Check out:
http://beej.us/guide/bgnet/html/multi/index.html
'Beej's Guide to Network Programming
Using Internet Sockets'
All you could possibly need to know about programming sockets for capture and manipulation.
If I were you I'd write it in C, I'm writing a similar project at the moment in C++ and it's hell but too late to stop and start again.
Hope that helps.
Bear in mind that you either need a router that you can re-program or you need to use your PC as a router to do this.
Either way you want to look into how IPTABLES are implemented.
I've never seen Desktop Windows used as a router only Windows Server, though it may still be possible. libpcap is for packet capture, but not interception as I understand it. Programs like Wireshark use it to monitor copies of packets, but not to modify them. If you want to attempt this, my impression has been that there is a lot more documentation and tools for doing something like this with NetFilter/IPTables on Linux. You can even install something like OpenWRT on a compatible router and get a small, cheap Linux router, though having Desktop Linux will probably help for development. The NetFilter QUEUE library can be used with some IPTables firewall rules to redirects specific (or all) packets to a regular user program. That program can then read the packet and modify it or even request it to be dropped.
http://www.netfilter.org/projects/libnetfilter_queue/
If you want to manipulate network traffic on a Windows machine (as you mentioned), you will need some extra software. This operating system wont give you the full control over itself, which is fine for some reasons.
I think what you want to do, should be done with either winpcap or win10pcap if you are using Win10. These packages contains a windows driver and the libpcap user space library.
I would like to create a chat application(desktop-app) in c++, so which protocol i would need to study and implement. UDP(?)
Please provide me some good thoughts and advices and links also.
UDP protocol is not the best choice for Internet chat program. UDP packets will be blocked by proxies. And UDP doesn't guarantee packets delivery. So probably TCP protocol will be a better choice.
Take a look on Boost.Asio Library. It already contains primitive implementation of chat program.
You don't give us much details here!
If your purpose is really to make a fully working and feature full chat application I suggest you look at XMPP which is an open instant-messenging protocol. Here is a list of some libraries implementing it.
If your purpose is to study network programming and you're more interested in UDP versus TCP for instance, then UDP is a bad choice for a chat application as it does not guarantee much about data integrity or ordering. Your messages might (and will!) be received in bad order or some might even be missing. TCP does that for kind of check for you.
In between (a very simple chat app) you can implement your very own protocol and use libraries others have suggested here like Boost.asio, ACE, POCO, or even wxWidgets and Qt, which will ease socket handling and also provide what you need to build a desktop app for the last 2.
Try using Boost.Asio. There are some examples of chat applications included in documentation.
You can use or look at an open-source networking library like ACE. A lot of goodies there.
You could use an existing library that handles instant messaging protocols, such as libpurple.
UDP is like a 'shoot and forget' kind of protocol. It's fast, but if you use it for communicating over the internet, there's no guarantee your messages will be recieved at all. Even if it's LAN, your packets can still be lost. It would be more convenient to use TCP which makes sure your packets arrive without errors and in the order you sent them.
I would like to be able to see and monitor my internet data (http/emule/email) on my own PC using Windows XP. I am thinking of something like WireShark but I would like to control it programmatically.
I would be using C or C++.
How can I do this?
WireShark uses winpcap to do it's thing.
Winpcap comes with a C interface.
winpcap is probably the most well known choice, but you could also write a Layered Service Provider. There's not a whole lot of documentation, but a good place to start is the article on msdn: http://www.microsoft.com/msj/0599/LayeredService/LayeredService.aspx
This has some advantages vs layer 2 packet parsing, but also some disadvantages. You'll need to evaluate where in the stack you want to live.
edit: Obviously, when I say pcap -- I really mean any similar approach. Obviously, winpcap was not the first driver/library combo to provide this sort of information.
Have a look at the code of the tool trafficWatcher. It uses WinPCap to distinguish between LAN and internet traffic.
The sourcecode is available here.