[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 5 of 9] xl: Add function to generate random uuid and use it



On Tue, 2010-07-27 at 17:02 +0100, Ian Jackson wrote:
> Gianni Tedesco writes ("Re: [Xen-devel] [PATCH 5 of 9] xl: Add function to 
> generate random uuid and use it"):
> > Nothing wrong with the patch but draws my attention to the fact that
> > this method seems far too likely to collide UUID's, for example in xl
> > invocations started during the same second. Why not use system entropy
> > pool? eg. scanf contents of /proc/sys/kernel/rand/uuid... I'm aware this
> > ought to be portable but PRNG can always be a fallback.
> 
> Yes.
> 
> We should probably use /dev/urandom (on Linux, or I think /dev/random
> on BSD).  If that's not available then we should use rand_r seeded
> with time and pid.

Or perhaps libuuid? It's is used by blktap2 so we already need it, at
least on Linux.

Ian.


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.