Re: notion of a local address [was: Re: ioctl SIOCGIFNETMASK: ip aliasbug 2.4.9 and 2.2.19]

["H. Peter Anvin" <hpa@zytor.com>]

Andrey Savochkin wrote:
> 
> It will work almost always, except cases where administrator set different
> preffered sources in local routes.
> I.e. it is indeed a very good approximation, but autofs shouldn't still hang
> or do nasty things if the check with the datagram socket shows that address
> isn't local, but in reality it happens to be local.
> A subtle misbehavior or loss of efficiency are acceptable, in my opinion.
> 
> Theoretically, it might be possible to create a configuration which gives
> false positive in this check, but I can't see how it may be harmful...
> 

If the check gives a false negative, autofs will create an NFS mount 
even though it's a local file (which may fail if the filesystem isn't 
exported, and is definitely slower.)

If the check gives a false positive, it will try a local bind (and 
probably fail) even though it is a remote filesystem.

	-hpa