On Tue, Nov 14, 2023 at 3:07 AM Chuck Lever III <chuck.lever@xxxxxxxxxx> wrote: > > > > On Nov 13, 2023, at 5:57 PM, Cedric Blancher <cedric.blancher@xxxxxxxxx> wrote: > > > > On Mon, 13 Nov 2023 at 17:19, Chuck Lever III <chuck.lever@xxxxxxxxxx> wrote: > >> > >> > >>> On Nov 10, 2023, at 2:54 AM, Martin Wege <martin.l.wege@xxxxxxxxx> wrote: > >>> > >>> On Wed, Nov 1, 2023 at 3:42 PM Benjamin Coddington <bcodding@xxxxxxxxxx> wrote: > >>>> > >>>> On 1 Nov 2023, at 5:06, Martin Wege wrote: > >>>> > >>>>> Good morning! > >>>>> > >>>>> We have questions about NFSv4 referrals: > >>>>> 1. Is there a way to test them in Debian Linux? > >>>>> > >>>>> 2. How does a fs_locations attribute look like when a nonstandard port > >>>>> like 6666 is used? > >>>>> RFC5661 says this: > >>>>> > >>>>> * http://tools.ietf.org/html/rfc5661#section-11.9 > >>>>> * 11.9. The Attribute fs_locations > >>>>> * An entry in the server array is a UTF-8 string and represents one of a > >>>>> * traditional DNS host name, IPv4 address, IPv6 address, or a zero-length > >>>>> * string. An IPv4 or IPv6 address is represented as a universal address > >>>>> * (see Section 3.3.9 and [15]), minus the netid, and either with or without > >>>>> * the trailing ".p1.p2" suffix that represents the port number. If the > >>>>> * suffix is omitted, then the default port, 2049, SHOULD be assumed. A > >>>>> * zero-length string SHOULD be used to indicate the current address being > >>>>> * used for the RPC call. > >>>>> > >>>>> Does anyone have an example of how the content of fs_locations should > >>>>> look like with a custom port number? > >>>> > >>>> If you keep following the references, you end up with the example in > >>>> rfc5665, which gives an example for IPv4: > >>>> > >>>> https://datatracker.ietf.org/doc/html/rfc5665#section-5.2.3.3 > >>> > >>> So just <address>.<upper-byte-of-port-number>.<lower-byte-of-port-number>? > >> > >>> How can I test that with the refer= option in /etc/exports? nfsref > >>> does not seem to have a ports option... > >> > >> Neither refer= nor nfsref support alternate ports for exactly the > >> same reason: The mountd upcall/downcall, which is how the kernel > >> learns of referral target locations, needs to be fixed first. Then > >> support for alternate ports can be implemented in both refer= and > >> nfsref. > > > > Just turn "hostname" into "hostport", i.e. the "hostname" string in > > the mountd protocol gets the port number encoded into it. Problem > > done. This is seriously a non-brainer, > > It's not as simple as you think. > > As far as I can tell, the mountd upcall/downcall already uses the "@" > character in the refer= value for another purpose. It has the same > problem as using ":" -- it would overload the meaning of the character > and make the refer= value ambiguous and unparsable. > > NFSD supports IPv4 addresses, IPv6 addresses, and DNS labels as the > hostname part of each fs_locations entry. DNS label support is one > reason we might have some difficulty using a universal address in > this interface -- the dot notation for the port number bytes looks > no different than the dot notation for subdomains, and we want to > enable alternate ports for both raw IP addresses and DNS labels. Which syntax does a DNS label have? Thanks, Martin
