Programming :: Reading/writing Every Frame On Ethernet?

Dec 3, 2010

I would like to write a program that can read every ethernet frame arriving on a specific hardware NIC, without a TCP/IP stack otherwise doing anything on that NIC. Likewise I want to be able to write out to that NIC. So every arriving ethernet frame, of all types, would be readable (probably one at a time to preserve frame boundaries). And every write of exactly that same data would send frames out. The data read and written would be the whole ethernet frame. The kernel would do nothing else with this data, but other NICs would still operate as usual.

What I would be doing is that on 2 separate NICs, copying frames from one to the other, as in bridging. But I would also be doing modifications per what my program needs to do (not at liberty to say what that would be). What facility would I need to be looking at to do this? There is no ethernet device file. Would raw sockets be able to do this? The programming language will be C.

View 4 Replies


ADVERTISEMENT

Debian Programming :: Sending Ethernet Frame Payload To Server

Nov 25, 2014

How can I send already encapsulated Ethernet frame payload to server? Basically what I would like to do is to is route Ethernet packages I get from other peripherals to their needed destinations and packets I receive send to requested device on peripheral. Program will be running on BeagleBone Black with Debian OS. Steps program should do from my point of view:

# <IPv6<UDP<DATA>>> packet received on some peripheral (UART in exact case) sent to server requested by <IPv6> destination address field# <IPv6<UDP<DATA>>> packet need to be sent to server that server application would receive <DATA> extracted from IPv6 and UDP encapsulation# <IPv6<UDP<DATA>>> packet need to be sent to server that server would know that device which is requested is available in BBB local network# <IPv6<UDP<DATA>>> packet received from server would be sent to requested device

From what I already found out I need to add routing header to packet I want to send and pass it to MAC encapsulation layer, or there is service which can add routing header and pass to other layers for me?

Also how can I get data sent from server, since if I'm not very wrong, system should receive them also encapsulated in Routing header, not as RAW data payload.

View 0 Replies View Related

Programming :: Reading And Writing Text Files In C?

Jan 1, 2011

Reading and writing text files in C?

View 9 Replies View Related

Programming :: Writing And Reading Driver Value In Ioctl?

Jan 18, 2011

I just want to read and write some values (integer) to my driver. I used put/get user but always getting errors.

driver

Quote:

int Wert;
static int device_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsinged long arg)
int ret;

[code]...

Quote:

int WERT
ret=ioctl(fd, SETIT, WERT)
ret=ioctl(fd, GETIT, WERT)

if i say in C++ WERT is 5 the value arg of the driver becomes 5 but not WERT the returnvalue of get and put user is -1 so it failed.

View 12 Replies View Related

Programming :: Reading And Writing White Spaces To A File?

Dec 2, 2010

I am trying to read a file character wise and trying to write the same character to another file. In this process, I unable to read and write white spaces successfully to the new file. The script reads the white spaces but while writing the white space is lost. The section of the code, is given below. Please advice how can i read and retain the white space while writing to a new file.

Code:

if [ -s f_test.txt ] && [ -f f_test.txt ]; then
echo "File Exists !!"
while read -n1 char; do

[code]....

View 2 Replies View Related

Programming :: Zip A Variable With PERL Without Reading Or Writing A File?

Jun 20, 2010

There is the Archive::Zip I think I can use with Perl 5.10 but I don't know how. I don't want to read or write any files, just zip something in memory, with best compression, like

$text = "this is a test";
$zippedtext = &Zip($text);
sub Zip {

[code]...

I guess it's only a few lines.

View 3 Replies View Related

Programming :: Multithreaded Reading And Writing Of A Shared Integer?

Nov 4, 2010

It it safe to read a shared integer while another thread is writing to it on a multicore system?

View 3 Replies View Related

Programming :: Writing To And Reading From A Socket From Bash Script?

Mar 11, 2010

Here the description of the issue I am having.I am writing a bash test script which reads lines from a file, builds ISO messages, sends them to a server, reads the response with response code and reports the result of the test to a file or on the screen.The message that I need to send is 94 characters long.Here's the portion of a code that I initially wrote:

~ Open socket.
exec 3<>/dev/tcp/172.26.0.25/9991
#~ Send msg.

[code]...

View 7 Replies View Related

Programming :: Line By Line Reading And Writing In Bash?

Nov 29, 2010

I have a text file (myfile.txt) with columns a,b,c.

123 2 23
124 2 24
125 2 22

[code]...

View 4 Replies View Related

General :: Dd Gets Slower While Reading And Writing?

Jan 25, 2011

user@user-laptop:~$ sudo dd if=sd_backup of=/dev/sdd bs=4M conv=noerror,sync

205520896 bytes (206 MB) copied, 28.564 s, 7.2 MB/s
247463936 bytes (247 MB) copied, 57.1285 s, 4.3 MB/s
260046848 bytes (260 MB) copied, 73.2388 s, 3.6 MB/s
289406976 bytes (289 MB) copied, 104.121 s, 2.8 MB/s

[Code]....

How come dd gets slower after copying this 8GB file? What can I do about it?

View 1 Replies View Related

OpenSUSE Network :: Direct NAS Reading And Writing?

Feb 9, 2010

I've been able to get access to our Netgear NAS, I can browse it, copy files etc. just fine. But I don't have "direct access" in as far as, Open Office won't open any files residing on the NAS, neither can I save directly to the NAS form a program and when I get a "Browse for File" form field on a website (eg attachments in GMail etc.), I can't browse to the NAS either. My XP box does do all of this, either through my mapped network drive or even through browsing the network. How can I make openSuse 11.2 use the NAS with my login credentials as if it was a local disk?

View 4 Replies View Related

Ubuntu :: Reading/writing Ext3 Partition From XP?

May 9, 2010

I've used ext2ifs drivers to mount my ext3 partition in winxp, but I don't have write acces, it's mounted in a read-only mode, and i didn't check the rad-only box during the installation of the drivers. [URL] It's a straithfoward proces so I dont understand what I did wrong. I'm using fresh xp install with (more or less) all the updates and ubuntu 10.04 Also the partition is mounted at /home, so I dont know if that makes any difference.

View 1 Replies View Related

General :: Reading/writing Ext3 Partiton From XP?

May 9, 2010

I've used ext2ifs drivers to mount my ext3 partition in winxp, but I don't have write acces, it's mounted in a read-only mode, and i didn't check the rad-only box during the installation of the drivers.I've used help from the official site http://www.fs-driver.org/and this tutorial http://www.dedoimedo.com/computers/l...s-windows.html
It's a straithfoward proces so I dont understand what I did wrong.I'm using fresh xp install with (more or less) all the updates and ubuntu 10.04Also the partition is mounted at /home, so I dont know if that makes any diferance.

View 3 Replies View Related

Security :: Reading/writing Encrypted NTFS?

Jul 25, 2010

My main workstation incorporates a mixture of ext3, ext4, and NTFS partitions scattered across a number of hard drives. Several of the ext4 partitions are encrypted, and I intend to encrypt the rest of the Linux partitions in the near future.I run VMware workstation, with several Windows OS guests, including Win2K, WinXP and Win7. My Win7 VM is installed on a virtual hard disk, and that virtual hard disk is encrypted using VMware facilities.So this leaves me with a bunch of NTFS partitions that are not encrypted. These are physical partitions on a couple of different hard drives. The reason I have them is ancient and historical, and as I have upgraded my system over time I have maintained the architecture due to the extreme difficulty of rearranging Windows systems.I still need to maintain Win2K and WinXP support, and rearranging those virtual machines would represent a hideous nightmare for me; I really want to maintain the same hard drive partition architecture.But I want to encrypt the NTFS partitions, in a fashion that can be handled by any of the Windows operating systems, AND can be accessed for read and write from Linux.Is this possible? If not using Windows facilities (I don't think ntfs-3g handles encryption, and there are known backdoors in the Windows facilities anyway), is there any third party solution that would work? Would True Crypt do the job in a fashion that would permit access from all the various operating systems, as required? I do generally mount the NTFS partitions in whichever Windows VM is appropriate, then share them out via SMB, but there are circumstances (like when a VM is not running) where I will directly hit them from Linux. So, it is possible for me to contemplate a solution that only works from Windows, but this would cost me the ability to repair/modify those filesystems directly from Linux, which under certain circumstances (a malfunction of the VM, for instance) could be a problem.

View 2 Replies View Related

Software :: Reading/Writing To Serial Ports (Rs-232)?

Dec 5, 2008

I am about to write a program to listen and read data from /dev/ttyS0 and write the data to /dev/ttyS1 after processing. Also, the same time I need to listen to /dev/ttyS1 and write to /dev/ttyS0 if any data arrived at /dev/ttyS1.

View 9 Replies View Related

Slackware :: Reading And Writing Emails From The Console?

Apr 3, 2010

I want to be able to access my email account from the console. I'm reading all day about fetchmail, postfix, sendmail etc. but all the stuff I found is related to building whole mail system. All I want to do is to read my emails and write some. Which is the painless way to do this? I successfully configured Evolution for this purpose but I want to do that from the console.

View 10 Replies View Related

Server :: Shortlist Processes Which Are Writing / Reading To / From Disks?

Apr 2, 2010

At times I see heavy hard-disk activity slowing down system.I have enough RAM and enough of it free.Apparently I am not doing anything that should cause this.'vmstat' shows high numbers for "bi bo" I want to find out which processes are doing "bi bo".How can I zero in on the particular processes?What command?

View 3 Replies View Related

Ubuntu Networking :: Samba Crashing When Reading / Writing Many Small Files?

Mar 18, 2010

Samba seems to crash and come back after some seconds if I copy a lot of small files in a short period of time over the network. How do I fix it?

I have Ubuntu 9.10 Server 64bit running on a D945GCLF2 board sharing two 1TB ext4 formatted HDDs to my Windows PCs using samba. I've been having an issue with reading or writing files through samba. It happens during copying operations or checksumming, anything that reads or writes MANY small files in a small amount of time. I am pretty sure the problem has to do with my server because the server has run on two different LANs in different homes and will crash from activity with any of several other PCs. There is no crashing if I access the files through SSH, although when I do that the max transfer speed is less than 1MB/s.

When I induce the crashing, there is absolutely no output to the server terminal.

As an easy access example of something that will crash samba, extracting Cinebench R11.5 to the server will do the job. It always fails.

View 9 Replies View Related

Ubuntu :: Pc Acting Slow When Reading / Writing Files From _ Onto Disk - Is That Normal?

Sep 27, 2010

Whenever I am busy reading or writing large files, or large sum of files, my computer is unresponsive. Screens are getting greyed-out and I just can sit there and wait until the reading/writing is done.
This is not caused by the CPU which is overstressed because it is not. Look at the attachments and you will see the CPU is used for about 20%. When these pictures were captured the computer was using hellanzb to unrar a long list of rar-files.
When you look at my signature you see the computer is not bad at all, just disk-access is slow. I can transfer files with a maximum speed of 30MB/s. Is that normal or is it very slow? I don't know the numbers. I have 2 SATA disks.
O.S. is Mint 9-Isadora, based on Ubuntu 10.04 and I use the 64-bits version.

View 9 Replies View Related

General :: After Writing Successfully A NAND Block Is This Reliable Ar Reading As A NOR Sector?

Apr 7, 2011

Am interested in using MT29F2G08AABWP NAND Flash memory for a new embedded design and I couldn�t find a clear specification regarding how reliable is the NAND flash vs. NOR for reading operation.If I program successfully a NAND block, read back and verify successfully the information and never erase or program that particular block again, can I assume that block will remain a good block and the information written there is safe for READING, roughly as safe as a NOR sector?

View 1 Replies View Related

Software :: Reading And Writing SAC (Seismic Analysis Code) Data Files In Fortran Codes

Dec 2, 2008

I synthesized a seismogram by using Fortran codes, I need plot the synthesized seismogram and the data together, so I can verify the accuracy of code. Now I encounter a question: how to read the SAC data by Fortran code, I have searched some codes on Internet, the details as follow:the velr12a.sac is my data file.

Code:
c read sac file
PROGRAM RSAC
PARAMETER (MAX=1000)
DIMENSION YARRAY(MAX)
CHARACTER*10 KNAME

[Code]....

View 2 Replies View Related

OpenSUSE Install :: Mount A Live Compressed File System For Reading & Writing From A LiveCD/DVD Image?

Jul 9, 2011

On a Linux CD/DVD, there are compressed filesystem images for the live version for KDE or Gnome for example, but they have no extension, but they are clearly an image file ( compressed filesystem images for the live version before installation ) !!

I was wondering, How do I mount these compressed filesystem images, after I copy the ISO content of the CD/DVD on my system .... I want to edit some files or packages and make some changes, like if I want to customize a live version of gnome for example ! ... ( I know you might be tempted to tell me to use KIWI etc to customize etc ..... ) ... but I want to be able to mount the compressed file system image, then edit it for reading and writing while it is in a subdirectory on its own ... i want to open it ! ... is there a way to do this ??? ... these type of files have no extension ...

i can open this compressed filesystem image then to edit for read & write ... before I roll it back again ..... If and when I succeed .... what should I watch out for ? ... will the same compressed file image but slightly modified work again ?

PS. that same question could be kind of translated or be extended like : how do I use unionfs/squashfs programs on the command line to mount these image files with no extension for read & write mode ???

View 9 Replies View Related

Programming :: Writing A TCP Server ?

May 2, 2011

I am going to write a TCP server program using c. Can anyone give me some advices on whats and what not to do specially when using select?

There would be a lot of data to be transferred both on the server and back to the client. I already have a simple server here but the server uses a lot of resources. Maybe 3 to 4 connections and the server's load would rise to unacceptable levels.

Which do you think is better to use fork or select?

View 4 Replies View Related

Programming :: Writing A Page In PHP?

Apr 21, 2010

I want to write some PHP for a website that'll have the data that the script will generate written inside a table with thin black line around it, much like LQ itself. My problem is: how do I draw the box that the text will be inside of, since the amount of text will vary - if I have a GIF with a picture of a box, that'll be of a fixed length, and my script can then only generate that much text, for it to look nice. Or do I need to fiddle with the GD library to get done what I want?

View 4 Replies View Related

Programming :: How To Implement Whole New Writing System

Aug 11, 2010

So basically, there is a really cool writing system I have been working on. It could be viewed (for simplification purposes) like an encryption method for the Latin script.

Facts about the writing system:
It has a little over 300 symbols.
It is syllable-driven.
It is highly compositional (eg. "c", "ca", "cae", "ca " and "ci." all map to different symbols - and NOT by overlaying elements)
Symbols have medium graphical complexity (comparable to Korean Hangul, or Japanese Hiragana)
Has a rather complex set of diacritics (~10, some of which can go on any symbol)
Has no ligatures

How transliteration occurs:
Sequences of Latin symbols map to certain symbols. Example below:[G][rou][p ][hu][g.]Characters sequences between "[" and "]" map to a single symbol (so it would take only 5 symbols to write "Group hug.").

How I want it to work:
I would like to have a daemon that: Intercepts all text displayed on the screen.
Converts it to my writing system (changes letter sequences with individual Unicode codes)
Leaves unsupported symbols unchanged.
Displays all the text on the screen using my font and characters intertwined with the fonts and characters left unchanged.

For example, if you take the following line of C++ code:for (i = 1; i <= n; i++)
I would like it displayed like this:[fo][r ]([i ]= [1]; [i ]<= [n]; [i]++)
Bold-symbols should be in my Unicode font with special symbols defined for this writing system, and the rest should be in its original font and encoding. Also, I would like this encoding to hold for display-purposes only. The data in the memory should remain unaffected. This also means real-time adjustments: if I open a text editor (say, from the OpenOffice Suite) and I start typing, I would like to see what I type encoded with my writing system, even though the document actually contains Latin letters. This also means that the symbol immediately before the cursor may change as you type.

View 3 Replies View Related

Programming :: Writing A Daemon That Can Update Itself?

Apr 27, 2011

I have written a daemon server. I would like to add the ability for the daemon to update itself. That is, it should be able to download the latest version of the code (when it receives a signal from a client) and then restart itself. I am stuck on getting the daemon to restart itself. The problem is killing the old daemon without killing the process that is starting the new daemon. In my latest attempt, the daemon that is updating itself runs a program in a subshell (using system) that starts a restarter daemon that runs the original daemon (again using system) with the restart command option. With the restart option, the new version of the daemon sends a terminate signal to the old version. Obviously, when I run the original daemon manually with the restart option, it restarts reliably. I figured that issuing the same restart command from a daemon would adequately isolate the process doing the restarting from the program being restarted. Using ps, I can see that the daemon does actually restart. However, the client locks. In fact, a few times, the OS locked and I had to reset.

View 7 Replies View Related

Programming :: Writing A Mkdir -p C Program

Apr 9, 2011

How to write a mkdir with -p option. I am struggling for creating subfolders. the chdir() is not working and thus subdirectories can't be created.

Code:

View 1 Replies View Related

Programming :: Writing File In Perl/cgi?

Apr 10, 2010

I'm not able to write to a file using my perl cgi script which is as fallows:

Code:
#!/usr/bin/perl -w
use strict;
print "Content-type: text/html

[Code]....

View 4 Replies View Related

Programming :: Writing Files Using O_DIRECT In C?

Feb 28, 2010

I am trying to write .pgm images using the O_DIRECT flag in open().I have a char* buffer which has the image data. I know that I have to align the buffers and have done that using posix_memalign() yet only a part of the image gets written.Has someone used O_DIRECT for writing files successfully?

View 1 Replies View Related

Programming :: Writing Console Application?

Jul 7, 2010

I'm trying to write a simple, console based application in linux, in c++. I know how to start in Eclipse and I have some experience in c++ from Windoze. I would like to ask, if there is some tutorial available on writing console apps. I mean, I know from using linux that there are two conventions on using parameters in command line (-v and --version for example).

View 2 Replies View Related







Copyrights 2005-15 www.BigResource.com, All rights reserved