1.\" Copyright (c) 2009 Rick Macklem, University of Guelph 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd April 25, 2009 28.Dt NFSCBD 8 29.Os 30.Sh NAME 31.Nm nfscbd 32.Nd 33.Tn NFSv4 34client side callback daemon 35.Sh SYNOPSIS 36.Nm nfscbd 37.Op Fl p Ar port_number 38.Op Fl P Ar client_principal 39.Sh DESCRIPTION 40.Nm 41runs on a client using 42.Tn NFSv4 43to handle callback requests from the NFSv4 server. 44If no 45.Nm 46is running, NFSv4 mounts will still work, but the server will never issue 47Open Delegations to the client. 48.Pp 49One callback server and one master server 50are always started. 51.Pp 52The following options are available: 53.Bl -tag -width Ds 54.It Fl p Ar port_number 55Specifies what port# the callback server should use. 56.It Fl P Ar client_principal 57Specifies the host based principal name to be used as the target for 58callbacks over RPCSEC_GSS. For KerberosV, it must be in the client's 59default keytab file. 60This client_principal should be the same one specified by the 61.Cm gssname 62argument being used by nfsv4 mounts. 63If you do not specify this argument, callbacks will still work over AUTH_SYS, 64which is what many extant servers use even for RPCSEC_GSS mounts, as of 2009. 65.El 66.Pp 67For example, 68.Dq Li "nfscbd -p 7654 -P root" 69starts the daemon to handle callbacks on port# 7654 and is using the host based 70principal root@<client-host>.<dns-domain> as the callback target. 71.Pp 72.Nm 73listens for service requests at the port 74defined by NFSV4_CBPORT in /usr/include/fs/nfs/nfs.h, unless 75.Fl p 76has been specified. 77For more information on what callbacks and Open Delegations do, see 78.%T "Network File System (NFS) Version 4 Protocol" , 79RFC3530. 80.Pp 81The 82.Nm 83utility exits 0 on success or >0 if an error occurred. 84.Sh SEE ALSO 85.Xr nfsv4 4 , 86.Xr mount_nfs 8 87.Sh HISTORY 88First introduced with the experimental nfs client for NFSv4 support in 2009. 89