Programming :: Passing Info From Mac To Network Layer
Dec 30, 2008
I want to implement a cross layer approach. I want to pass the network information such as delay from the MAC layer to Network layer. Can you tell me the way I am new to this. I am using linux (fedora). I think some system call will do the trick. Correct me if I am wrong. (I want to implement QoS matrices)
Ive read a few books and a lot of tutorials on C but can't find this topic explained in a deliberate way.I can find bits and pieces but nothing thorough.
im trying to send pages of 4096 bytes from kernel layer of server to kernel layer of client over a network. previously i tried the foll. code , for data less than a 100 bytes it worked fine , but for something larger than that the computer hangs......(even the dmesg's wont say why) i also wanted to know how we could use the 'sendpage' function to solve this problem.
I want to know the IPsec-Advantages and Disadvantages that arise because of its location on the network layer in the OSI-Model. I read rfc2401 and rfc4301 specifications to find out the advantages and disadvantages of IPsec being located on the network layer in the OSI-Model (equivalent to Internet layer in the TCP/IP protocol stack). I really could not find enough good reasons for the advantages and disadvantages of IPsec being located on network layer. Here are some of them that I could think of:Advantage: - No application-specific implementation is needed (in comparison to SSL/TLS) - The ability to connect two subnets on the internet (tunneling mode) - Ability to encrypt the traffic between two end-points (transport mode)Disadvantage: - Complex implementation of ipsec itself - High computation performance when AH and ESP both activated - No encryption for the packets to the destination if it is arrived on the subnet on the other side when tunneling mode is activated.
(the network traffic is no more encrypted inside the subnet)What else can you guys add more to these advantages and/or disadvantages? The focus is IP-sec location on the network layer. (it is a kind of comparison to ssl/tls which is upper layer protocol)I would be grateful to any responses.P.S: I hope that this thread has landed in its right place.
works fine at moving all files anywhere below the current directory to the current directory.
My question is can it be modified so it only moves all the files up one directory layer? Otherwise I shall have to cd 100 or so times and run it in each directory i want to compress...
I imagine the directory below which the file is stored is in the % somewhere it is just a case of extracting it and applying it to the mv command, yes?
Our ISP provides us with Layer 2 hardware (Modem?/Switch? (Hatteras)) for our leased line and internet access. I have been told that I should set up a VLAN capable router to separate the internet traffic from the internal traffic. I found that linux is capable of VLAN routing. Nice!
I have setup opensuse 10.3 put in two NICs and did the following vconfig add eth0 10 vconfig add eth0 20 ifconfig public.ip.add.ress netmask 255.255.255.252 eth0.10 up ifconfig 192.168.0.1 netmask 255.255.255.0 eth0.20 up
Plugged this NIC into the HATTERAS hardware (with a straight cable), and thought that this way I should be able to ping the public gateway or any ip out on the internet. My ISP is telling me that I should create a VLAN trunk to be able to 'use the internet', but as I understand in linux if I create any number of VLANs on one NIC they are already trunked. I also got the info, that the traffic is tagged, and I can separate the traffic reading the tags. I already read that some NICs are not able to VLAN because they are not able to handle the increased packet size.
Also that the MTU setting is important (dono' the exact value though, only that its important). I thought that a linux machine can act as a router and firewall in such a case, because proprietary switches/routers use linux as embedded os. This is my first meeting with VLAN so if this whole post does not make any sense or you think that I just need to RTFM more then tell me! I also have some (3) Dlink 3226 Layer2 switches around, but I think it would be waste to use a 24 port switch on this subject.
I'm struggling with the issue of passing a vector of a class to itself, here's what state its in now... (tried many variations, but without direction).
I'm trying to work out the best way to achieve the following.
1)php page that grabs data from a local database. (not a problem)
2)It then needs to send this data to a c program/service running on a remote server. (I probably need it to be able to handle 4+ million reocrds in an array)
3) The c service then needs to process the data and send it back to the initial php script that called it. i was hoping this could be in a an array like structure of some kind. 4)update the db with the results.
I was thinking of using gsoap to write a simple c soap service that php can communicate with. Would this be the right way of doing this or would something like sockets in php be a better way of sending this volume of data as an array or struct to linux c socket if thats even possible.
I am having a situation where I couldn't connect to Internet through wireless and LAN cable. I have done ifconfig, it only shows me "lo" info. May I know how can I bring up the LAN and wireless?
i'm programming a small tcp client, but i need that the server knows the source ip. My client receives a external connection and forwards, but the ip seen by the server, of course, is the client ip. I would like, change this ip to original source ip.
I don't know how to do this. I tried with the connect and select function.
I have a file with around 1000 IP addresses in it and I need to be able to ssh into each one of them, run a single command, and then exit. I already know the ssh command I want to run and it looks like this:
(I know shpass is not good to use and keys are the correct way but I don't have any other options in this scenario.) if these ip addresses were in a .csv file, by themselves with no other information, how would I create a script to do the above command to each ip until the end of the file?
and lang.php has a link to page2.html, how do I pass on the value of the lang parameter from lang.php to page2.html? The value needed is the one passed in to lang.php.
An input filename ($1) is fed into mediainfo, which by the use of grep and cut spits out a single number which is the aspect ratio. This is then divided by bc into 320, which gives the desired height dimension for the file that I want ffmpeg to create for me. Finally, ffmpeg runs using the calculated dimensions... Basically, it's the passing of the $ASPECT variable to bc that seems to fail. It looks like bc won't read the output from the mediainfo line... It always crashes out with:
Code:
(standard_in) 1: illegal character: ^M I've tried doing something even simpler like this to debug by just trying it to display the calculation on the screen:
We have a ubuntu machine on the network with number of users in it. Basically, when other users connect via telnet i want then to get particular messages depending on the user. The message will be set by the administrator or a particular user with privs. Similarly we also need a to-do app via which users can update their work and see each others progress . Its all in a local network. Do tell what would be the best way to do it!
The etckeeper code will work well as a template, but I need to pass a parameter between the pre- and post- instances. The parameter is obtained from the pre- invocation and passed to the post- invocation.I know that something similar to my quest is done with the 'pid' but how to do it in the 'standard' way. Happily there can't be multiple dpkg instances running concurrently (prevented by dpkg?) so I don't have to worry about that issue.
Q1. What is the 'standard' way of passing parameters about?
Code: Select allsnapper -c etc create -t pre -p (which 'prints' the parameter (int) to pass to the following invocation) snapper -c etc create -t post --pre-number <parameter> in place of the two etckeeper calls.
Q2. How do I pick up the 'printed' output of the 'pre' call? I think it's just a 'get' from the stream but perhaps I've missed something.?
I am trying to simulate a shell. So what I do is checking of having the parameters from standard input, suc as "/bin/ls -l /home/france/Documents", and then passing them to function execute, which at some point calls execvp(argv[0],argv)The problem is that I don't succeed in using these arguments, while if I call execvp(paramList[0],paramList) it works!!!! Where paramList is exactly what I would put on standard input, but defined statically.
I started to run a C++ my program in Linux and I don't know how to test my program that works fine with a text file. This is a project for my uni and to explain more clear, My program is a sample database for modify or add and search and it read data from a binary file and also write into a binary file. I have got an input from my lecture and she said after compiling in Linux I must write:
1-to compile: Code: g++ (files with cpp) 2-to see the output: Code: ./a.out 3-to test with input: Code: ./a.out < input.txt >
My problem is in step three. What I must write in the command part after" step2" to see the output?
This is a client server issue where the server creates a new thread for listening to a new client, now when the thread starts execution and during its execution the server needs to pass it an object of some X class, how's that to be done?
what I am trying to do is to pass an argument to the standard input stream of a child process. I mean I create two programs .. first one invokes the other. second one contains something like
Code:
scanf("%d", &n);
now I want my first program to be able to pass a value to the second one so that it gets stored in n.
I am calling another executable in my application (C programing) using "system" command which is user interactive program. now i want to pass those args in system command only.
system(" executable ");
Executable will expect 1,2 or 3.
1 is to continue 2 for do changes in settings 3 exit from application
I am trying to pass an array to thread program. Its printing the val[0] value but its not printing value at val[1]. Can somebody help me with this problem.
I am working on a daemon that I want to change some variables while its running. Is this possible?I want to implement a command line type interface for my daemon so I can send it commands that will change the current values of specific variables, and also be able tell the daemon to load/save a config file.The only thing I have found so far is passing arguments to a daemon, but that seems to be a one-time shot when your first starting it.