Is their any open source project based GRE? - c

I want to build one network system which can make client communicate thought NAT? any suggestion ?

RFC 1701 can be implemented using ifconfig and route. You don't really need C code AFAIK. I do not know of open source to create what you specified.
The qnx site has an example:
http://www.qnx.com/developers/docs/6.4.0/neutrino/technotes/gre.html
A linux example:
http://tier.cs.berkeley.edu/drupal/howto/ip-tunnel-using-gre-on-linux

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Retrieve network camera stream URL in Linux

I am trying to retrieve rtsp URLs of cameras on my network. I can do this using Onvif Device Manager on Windows but how to do this on Linux using C/C++ or command line tool. I have tried various libs e.g. onvifc (OpenCVR) and onvifcpplib but none of them could compile on Linux, neither they have API documentation. Any suggestions please!
I was able to find a gsoap-onvif solution from https://github.com/tonyhu/gsoap-onvif. This programs successfully retrieves parameters from most of the Onvif complaint cameras.
you can have a try with python onvif, some feature you can use, may be other feature such as PTZ you can use .
also, you can have a try with opencvr's another project, https://github.com/veyesys/h5stream, if you can't compile,you can download from sourceforge.
Good luck.

TCP/IP Programming in C

I have an exam on tomorrow on TCP/IP programming. Following is one of the previous question on this paper.
Write and run a client and a server program. Using C language in UNIX, with the
following specifications :
• A TCP client program will send a range of number (e.g. 1 to 10) to the server.
• TCP server accept the number range from client and send back the sum of the
number range. Client will print the result.
I dont know how to setup the compiler and other settings to run this tcp ip programs. When I search online, I got two different programs, one for Client and another For server. Some please tell me how can i run these programs to get desired output. What kind of compiler should I install on my system.( I am using windows 7) ??
Since the assignment requires your code to work on a Unix system, you first need to install one. Follow these simple steps to install a virtual Unix environment on top of your existing Windows installation.
Download and install VirtualBox for Windows.
Download & unpack this Ubuntu 12.10 disc image (NOTE: Requires 7-Zip).
Launch VirtualBox and create a new Virtual Machine (name it Ubuntu).
In the "Virtual Hard Disk" settings, select "Use existing hard disk" and select the image file you just downloaded (NOTE: It's filename should end in ".vdi").
Run your new Virtual Machine. You should see the Ubuntu splash screen.
Login with username ubuntu and password reverse (NOTE: Case Sensitive!).
Open up Terminal and type sudo apt-get install build-essential (NOTE: when Terminal prompts you for a password, use reverse).
You should (with hope) have everything you need for your assignment. For more information on network programming, consult Beej's Guide to Network Programming -- Using Internet Sockets.
You need to open two different terminals on your system.
In the first terminal compile and run the server.c program.(make sure either you listen to all ips or your host ip(atleast).
while this is running.(it will wait for a request from your client program)
Run the client program in the other terminal.
Hope this solves the problem!
For details on how to create and run a file in unix refer http://www.wikihow.com/Compile-a-C-Program-Using-the-GNU-Compiler-%28GCC%29
P.S: you can do the same in win7 if iam not wrong only that terminal here in called command prompt!
Post the results if possible!
Download a thing called VMWare player. And look for a Ubuntu image that you can load with the VMWare player. That way, you will have a little Linux virtual machine that you can run inside or along with Windows 7. You can use the compiler GCC in your Ubuntu or whatever other Linux virtual machine. And get lots of coffee. Blargle is correct, but I think my suggestion is a little better, because you end up having a fairly complete Unix type environment to develop in. Blargle's way put Unix tools on top of Windows, which I find to be kind of clunky.
I learnt socket programming from this site. He has given everything in detail . Download an Vmware workstation and load up ubuntu . Understand the programs they are pretty much straight forward .
Maybe you can try to look at Network Socket on the web. You can easily find a lot of good tutorial that can answer your question.
You can use the compiler you want on your system, depending on what are you using now.

Send data from local webpage to C program running locally

I'm looking for the simplest possible (cross-platform, but not necessarily cross-browser) code to send data from a local web page to a C (not C++) application running locally. Basically, I have an HTML page with a form and I want to send the data from that form to another process in the simplest way possible. (I know that I can read local data from a webpage relatively easily, especially now with HTML5, but writing outside of the javascript sandbox is a mystery.)
I know that browsers make this very hard to do for security concerns, and I don't want to open up my machine to attacks, but maybe I can run a very simple server inside the C application to receive the submitted data... Either way, I cannot run any standard webserver, so I need to have a C library/app that does it for me.
I've looked into .hta files (seem to only work for Windows) and some C web servers (all I've found are *nix specific). A similar question is how to transfer of data from webpage to a server c program , except that user allows the use of Java and other webserver platforms (I must use C).
UPDATE: Promising libraries: https://stackoverflow.com/questions/175507/c-c-web-server-library
Have you considered FastCGI? I have a fast CGI library written in C that might be helpful. It still needs a lot of work and I'm not sure if I would want to use in a production environment.
If you find any bugs or make any enhancements, please share them so that it can help others.
https://github.com/manvscode/shrewd-cgi
You could write a very simple web server in C, serve the page from it (avoids security issues), and post the form to it.
If you're bound to c, you'll have to go low-level and deal with all the nifty details around the sockets library. (There's a reason why people abstract that in high-level languages). Check out some example code for RPC in C with server and client here. If you can afford to bind to C, e.g. using Tcl, i would implement the server in a tcl script and bind your C functions as a Tcl command. That way you pass the content directly to your c method while avoiding to write all the sockets code low-level.
Send the desired data from web to specific port of your system (for example port X). Then run your application (e.g. APP) in background using following command:
nc -l X | ./APP
And of course you need nc package.

SNMPd: Cannot open /proc/bus/pci

I cross-compiled NET-SNMP 5.7.1 from sources to a PowerPC using ELDK-3.1.
When I try to load the snmpd daemon in my embedded board, I see the message:
# snmpd -f -Lo
pcilib: Cannot open /proc/bus/pci
pcilib: Cannot find any working access method.
Of course my PPC board has no PCI, and I wonder why is netsnmp looking for it.
In more than one place I see this same message (sourceforge, mail-archive, google-groups), but ir has no answer at all. Another variant, with a little but unhelpful responses at (archlinuxarm).
Can anybody please help me?
I'm assuming you're on a Linux target.
Net-SNMP's changelog lists "[PATCH 3057093]: allow linux to use libpci for creating useful ifDescr strings".
The configure script will search for an available libpci, and, having found one, will define
HAVE_PCI_LOOKUP_NAME and HAVE_PCI_PCI_H. To disable this code: after configuring, you can change those defines in include/net-snmp/net-snmp-config.h, then rebuild. The affected code is in agent/mibgroup/if-mib/data_access/interface_linux.c.
There's also a patch in this bug report: http://sourceforge.net/p/net-snmp/bugs/2449/
I resolved the issue using the stock snmpd that comes with the Raspbian.
In /etc/snmp/snmpd.conf file I isolated the issue to the following line
agentAddress udp:161,udp6:[::1]:161
Instead of listening on all interfaces, if I specify the the ip address of the eth0 interface i.e.:
agentAddress udp:10.0.1.5:161,udp6:[::1]:161
Then snmpd starts fine.
My speculation is that the stock snmpd tries to enumerate all possible interfaces including the pci ones.

HINTERNET InternetOpenUrl() on linux C

I am a native windows programmer and I was just starting to develop some applications on linux. I was wondering if there is a linux function similar to InternetOpenUrl(). I wanted to use this so I could open the Speakeasy speed test to download random images according to size to "speed test" internet connections. If there isn't a similar command does anyone have some C code for initiating a http socket to a server to download a file (or code to do the same on a ftp although i rather not use ftp). I would rather use the InternetOpenUrl() alternative if there is one but i am also open to other methods as well.
You're looking for libcurl, which incidentally also works on Windows.

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