Random number generator in Linux kernel

Random number generator in Linux kernel

[Vineet Joglekar]

Hi all,

Can someone please tell me where can I find and which random/pseudo-random number generator can I use inside the linux kernel? (2.4.28)

I found out 1 function get_random_bytes() in linux/drivers/char/random.c but thats not what I want.

I want a function where I will be supplying a seed to that function as an input, and will get a random number back. If same seed is used, same number should be generated again.

Can anybody please help me with that?

Thanks and regards,

Vineet.

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Re: Random number generator in Linux kernel

[Darío Mariani]

As far as I understand the kernel generates random numbers gathering
data from several entropy sources, you will never get repetability
from there. Two options I know of:

1) The standard C library has the functions rand and random, wich
seems to have a decent distribution of the random numbers.

2) If you use C++, the Boost library (www.boost.org) has an excelent
set of options for generating random numbers.

              Darío

On Mon,  7 Mar 2005 18:18:53 -0500 (EST), Vineet Joglekar
<vintya@excite.com> wrote:
> 
> Hi all,
> 
> Can someone please tell me where can I find and which random/pseudo-random number generator can I use inside the linux kernel? (2.4.28)
> 
> I found out 1 function get_random_bytes() in linux/drivers/char/random.c but thats not what I want.
> 
> I want a function where I will be supplying a seed to that function as an input, and will get a random number back. If same seed is used, same number should be generated again.
> 
> Can anybody please help me with that?
> 
> Thanks and regards,
> 
> Vineet.
> 
> _______________________________________________
> Join Excite! - http://www.excite.com
> The most personalized portal on the Web!
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> 


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Re: Random number generator in Linux kernel

[Erik Mouw]

On Mon, Mar 07, 2005 at 06:18:53PM -0500, Vineet Joglekar wrote:
> I want a function where I will be supplying a seed to that function
> as an input, and will get a random number back. If same seed is used,
> same number should be generated again.

Google for "Numerical recipes in C", it has a complete section about
random numbers, including a couple of functions that do what you want.


Erik

-- 
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| Lab address: Delftechpark 26, 2628 XH, Delft, The Netherlands

Re: Random number generator in Linux kernel

[selvakumar nagendran]

        I think ur idea of generating a random number
with a seed will not be effective. The kernel comes up
with true random number generation by using the random
interaction of device drivers with the kernel. I think
that will be more effective than ur logic. It provides
true randomness and it avoids any guess. 
For more details u please refer the book ' Linux
kernel development' by Robert M Love Appendix C kernel
Random Number Generator. If u still want to stick to
ur own logic then u can implement it as a function
inside the kernel.

Regards,
selva

--- Vineet Joglekar <vintya@excite.com> wrote:
> 
> Hi all,
> 
> Can someone please tell me where can I find and
> which random/pseudo-random number generator can I
> use inside the linux kernel? (2.4.28)
> 
> I found out 1 function get_random_bytes() in
> linux/drivers/char/random.c but thats not what I
> want.
> 
> I want a function where I will be supplying a seed
> to that function as an input, and will get a random
> number back. If same seed is used, same number
> should be generated again.
> 
> Can anybody please help me with that?
> 
> Thanks and regards,
> 
> Vineet.
> 
> _______________________________________________
> Join Excite! - http://www.excite.com
> The most personalized portal on the Web!
> -
> To unsubscribe from this list: send the line
> "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at 
> http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 


	
		
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Re: Random number generator in Linux kernel

[Bill Davidsen]

Vineet Joglekar wrote:
> Hi all,
> 
> Can someone please tell me where can I find and which
> random/pseudo-random number generator can I use inside the linux
> kernel? (2.4.28)
> 
> I found out 1 function get_random_bytes() in
> linux/drivers/char/random.c but thats not what I want.
> 
> I want a function where I will be supplying a seed to that function
> as an input, and will get a random number back. If same seed is used,
> same number should be generated again.

Without knowing what you're doing I can't say if it justifies having all 
that extra code around, but the stuff from the library, like srand48, 
will do this. You can add the code to your module.

-- 
    -bill davidsen (davidsen@tmr.com)
"The secret to procrastination is to put things off until the
  last possible moment - but no longer"  -me