This patch moves the definition of struct rnd_state and the inline
__seed() function to linux/random.h. It renames the static __random32()
function to prandom32() and exports it for use in modules.
prandom32() is useful as a privately-seeded pseudo random number generator
that can give the same result every time it is initialized.
For FCoE FC-BB-6 VN2VN mode self-selected unique FC address generation, we
need an pseudo-random number generator seeded with the 64-bit world-wide
port name. A truly random generator or one seeded with randomness won't
do because the same sequence of numbers should be generated each time we
boot or the link comes up.
A prandom32_seed() inline function is added to the header file. It is
inlined not for speed, but so the function won't be expanded in the base
kernel, but only in the module that uses it.
Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The rationale is:
* use u32 consistently
* no need to do LCG on values from (better) get_random_bytes
* use more data from get_random_bytes for secondary seeding
* don't reduce state space on srandom32()
* enforce state variable initialization restrictions
Note: the second paper has a version of random32() with even longer period
and a version of random64() if needed.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- Let it update the state of all CPUs. The network stack goes
into pains to feed the current IP addresses in, but it is not very
effective if that is only done for some random CPU instead of all.
So change it to feed bits into all CPUs. I decided to do that lockless
because well somewhat random results are ok.
v2: Drop rename so that this patch doesn't depend on x86 maintainers
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make net_random() more widely available by calling it random32
akpm: hopefully this will permit the removal of carta_random32. That needs
confirmation from Stephane - this code looks somewhat more computationally
expensive, and has a different (ie: callee-stateful) interface.
[akpm@osdl.org: lots of build fixes, cleanups]
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Stephane Eranian <eranian@hpl.hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
