Re: RPC request sent to 127.0.0.1 becomes from other IP on machine

Ok, I had a hunch it was related to the use of jails.
I am just testing a patch that switches the nfsuserd over to
using an af_local socket, so this will be avoided.
(I think it makes more sense anyhow. I just never got around
 to doing it.;-)

Thanks for the info, rick

----- Original Message -----
> On Thu, 10 Dec 2015, Rick Macklem wrote:
> 
> > Hi,
> >
> > Mark has reported a problem via email where the nfsuserd daemon sees
> > requests coming from an IP# assigned to the machine instead of 127.0.0.1.
> > Here's a snippet from his message:
> >   Ok, I have Plex in a jail and when I scan the remote NFS file share the
> >   *local* server's nfsuserd spams the logs.
> > Spamming the logs refers to the messages nfsuserd generates when it gets
> > a request from an address other than 127.0.0.1.
> >
> > I think the best solution is to switch nfsuserd over to using an AF_LOCAL
> > socket like the gssd uses, but that will take a little coding and probably
> > won't be MFCable.
> >
> > I've sent him the attached patch to try as a workaround.
> >
> > Does anyone happen to know under what circumstances the address 127.0.0.1
> > gets replaced?
> 
> My memory is quite hazy on this subject, but I think that outbound traffic
> from a jail is not permitted to use the system loopback address 127.0.0.1;
> traffic from this address within a jail gets replace with the jail's
> primary IP address.  It is possible to specify an alternate loopback
> address for use within the jail (e.g., 127.0.0.2) and if that alternate
> address is only bound within the jail, it can be used for outgoing traffic
> to the host.  See jail.conf(5); I appear to have something like:
> 
> kduck {
>     host.hostname = "kduck.mit.edu";
>     ip4.addr = lo0|127.0.0.2, 18.18.0.52;
> [...]
> }
> 
> Note that there may be some additional magic about the primary address of
> the jail being first (or last?) in the list of addresses.
> 
> -Ben
> _______________________________________________
> freebsd-current_at_freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-current
> To unsubscribe, send any mail to "freebsd-current-unsubscribe_at_freebsd.org"
>