Re: [NFS] NFS inconsistent behaviour

From: Frank van Maarseveen
Date: Wed Oct 18 2006 - 16:10:25 EST


On Wed, Oct 18, 2006 at 03:26:20PM -0400, Trond Myklebust wrote:
> On Wed, 2006-10-18 at 20:38 +0200, Frank van Maarseveen wrote:
> > I ran out of privileged ports due to treemounting on /net from about 50
> > servers. The autofs program map for this uses the "showmount" command and
> > that one apparently uses privileged ports too (buried inside RPC client
> > libs part of glibc IIRC). The combination broke autofs and a number of
> > other services because there were no privileged ports left anymore.
>
> Yeah. The RPC library appears to always try to grab a privileged port if
> it can. One solution would be to have the autofs scripts drop all
> privileges before calling showmount.
>
> I suppose we could also change the showmount program to create a socket
> that is bound to an unprivileged port, then use
> clnttcp_create()/clntudp_create().
>
> We could probably do the same in the "mount" program when doing things
> like interrogating the portmapper, probing for rpc ports etc. The only
> case where mount might actually need to use a privileged port is when
> talking to mountd. Even then, it could be trained to first try using an
> unprivileged port.

If we could fix why there are that many connections in state TIME_WAIT
then using privileged ports would not be a problem either.

--
Frank
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