"J. Bruce Fields" <bfields-uC3wQj2KruNg9hUCZPvPmw@xxxxxxxxxxxxxxxx> writes: > > On Mon, Mar 19, 2012 at 01:06:47PM -0400, Rick Macklem wrote: >> >> I wrote: >>> >> > J. Bruce Fields wrote: >>>> >> > > On Mon, Mar 12, 2012 at 05:27:08PM -0400, J. Bruce Fields wrote: >>>>> >> > > > On Mon, Mar 12, 2012 at 05:14:16PM -0400, Chuck Lever wrote: >>>>>> >> > > > > IMO, the server should do a comparison of the nfs_client_id4 >>>>>> >> > > > > strings, and nothing else. >>>>> >> > > > >>>>> >> > > > We're supposed to return CLID_INUSE when we see a setclientid >>>>> >> > > > from a "different" client using the same string, to keep >>>>> >> > > > clients from doing mischief with other clients' state (either >>>>> >> > > > maliciously or, as in this case, accidentally). >>>>> >> > > > >>>>> >> > > > "Different" here is defined as "not having the same principal". >>>>> >> > > > I know what that means in the krb5 case, but I'm less certain >>>>> >> > > > in the auth_sys case. >>>> >> > > >>>> >> > > Cc'ing the ietf list. Is it reasonable for a server to expect >>>> >> > > setclientid's to come from the same client IP address at least in >>>> >> > > the auth_sys case, or could that break multi-homed clients? >>>> >> > > >>> >> > I think that even a dhcp lease renewal might result in a different >>> >> > client IP, if the client has been partitioned from the dhcp server >>> >> > for a while. > > > > Yeah, but by that point the client's v4 lease is probably expired > > anyway so the client's not likely to be bothered by the NFS4ERR_INUSE. > > >>> >> > I'm not convinced that different client IP# implies different >>> >> > client. (Even "same ip# implies same client" might not be true, if >>> >> > the dhcp server assigned the IP# to another machine while the >>> >> > client was partitioned from the dhcp server, I think? I haven't >>> >> > looked at current dhcp implementations, but it seems conceivable to >>> >> > me.) >>> >> > >> >> Oh, and what about the case of 2 clients that are sitting behind the >> >> same NAT gateway? (I think they'd both be seen as having the client >> >> host ip# of the gateway, but with different TCP connections on >> >> different client port#s.) > > > > Well, sure, but all I'm proposing here is returning NFS4ERR_INUSE in the > > case where we get setclientid's with the same client-provided id. At least in the case that sparked this discussion, it would already be enough to return NFS4ERR_INUSE only if the client id is being reassigned *and* has a 0.0.0.0 (aka autodetection failed) value. Best, -Nikolaus -- »Time flies like an arrow, fruit flies like a Banana.« PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6 02CF A9AD B7F8 AE4E 425C -- 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
