On Fri, Nov 08, 2013 at 11:28:02AM -0500, Steve Dickson wrote: > > > On 08/11/13 11:22, J. Bruce Fields wrote: > > On Fri, Nov 08, 2013 at 11:19:45AM -0500, Steve Dickson wrote: > >> > >> > >> On 08/11/13 11:17, J. Bruce Fields wrote: > >>> On Fri, Nov 08, 2013 at 11:10:14AM -0500, Steve Dickson wrote: > >>>> > >>>> > >>>> On 08/11/13 10:12, Jeff Layton wrote: > >>>>> On Fri, 08 Nov 2013 10:00:02 -0500 > >>>>> Steve Dickson <SteveD@xxxxxxxxxx> wrote: > >>>>> > >>>>>> > >>>>>> > >>>>>> On 08/11/13 08:22, Jeff Layton wrote: > >>>>>>> On Fri, 08 Nov 2013 07:41:32 -0500 > >>>>>>> Steve Dickson <SteveD@xxxxxxxxxx> wrote: > >>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> On 07/11/13 18:05, Chuck Lever wrote: > >>>>>>>>> > >>>>>>>>> On Nov 7, 2013, at 1:35 PM, Steve Dickson <SteveD@xxxxxxxxxx> wrote: > >>>>>>>>> > >>>>>>>>>> Hey mrchuck... > >>>>>>>>>> > >>>>>>>>>> On 07/11/13 14:25, Chuck Lever wrote: > >>>>>>>>>>> Hi Steve- > >>>>>>>>>>> > >>>>>>>>>>> On Nov 7, 2013, at 11:09 AM, Steve Dickson <steved@xxxxxxxxxx> wrote: > >>>>>>>>>>> > >>>>>>>>>>>> This new module parameter makes the v4 client > >>>>>>>>>>>> use the minimal authentication flavor (AUTH_UNIX) > >>>>>>>>>>>> when establishing NFSV4 state and doing the > >>>>>>>>>>>> pseudoroot lookup > >>>>>>>>>>> > >>>>>>>>>>> The patch description doesn't say, but is this change to work > >>>>>>>>>>> around the 15 second GSSD upcall timeout? > >>>>>>>>>> Yes. A 15 second delay on every mount due to security that > >>>>>>>>>> nobody is requesting is just not good.. IMHO.. > >>>>>>>>> > >>>>>>>>> One thing we haven't discussed is reducing the upcall timeout to 5 seconds or less, > >>>>>>>>> as a form of immediate relief. 15 seconds is arbitrary, and is onerous even when > >>>>>>>>> you expect the mount to work (ie why would it be good for any properly configured > >>>>>>>>> environment to take 15 seconds to establish a GSS context?). > >>>>>>>>> > >>>>>>>>> In other words, there are still cases where users wait 15 seconds unnecessarily, > >>>>>>>>> and not because of the use of krb5i for lease management. Aren't those of concern? > >>>>>>>> No. I think the concern here, at least my concern, is the lack of management. > >>>>>>>> We are forcing admins to use krb5i in lease management when its not necessary > >>>>>>>> and there is no way to turn it off. > >>>>>>>> > >>>>>>> > >>>>>>> I don't think that's really the case. The idea was to have the client > >>>>>>> attempt to use krb5i if it's available, and then to fall back to > >>>>>>> AUTH_SYS if it isn't. This would be *absolutely* no big deal if the > >>>>>>> GSSAPI upcall succeeded or failed immediately instead of requiring this > >>>>>>> timeout when the daemon isn't running. > >>>>>> What server makes krb5i available today in state setup and pseudoroot lookups? > >>>>>> > >>>>> > >>>>> That I don't know...sorry... > >>>> Then what is the justification to take all these extra steps > >>>> there they going to fail %100 of the time?? > >>> > >>> Any server can support krb5 for state setup and pseudoroot operations if > >>> it's configured. This isn't a problem. > >> Would is this done on a Linux server? Is there a wiki? > > > > It's allowed by default, there should be nothing to configure beyond the > > usual krb5 setup. > Great! So you are saying when rpc.gssd is up and Kerberos is correctly > configured on both the server and client the state setup and pseudoroot > become secured? Yes. There's one possible exception: I think mountd currently may not allow krb5 on the pseudoroot if it's not allowed on some export? We could fix that if it's a problem here. (I don't think it is, because a client mounting with auth_sys will fall back on auth_sys in this case, and a client mounting with sec=krb5 is going to fail eventually anyway.) The server will allow state setup regardless. > And this is the case with other non-Linux servers? Yes, the client's always used krb5 for all that setup at least in the case where the first mount uses sec=krb5. And we test that at connectathon/bakeathon, and it's probably one of the first things anyone writing new gss support for a server would try. --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
