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.Dd April 25, 2009 26.Dt NFSCBD 8 27.Os 28.Sh NAME 29.Nm nfscbd 30.Nd 31.Tn NFSv4 32client side callback daemon 33.Sh SYNOPSIS 34.Nm nfscbd 35.Op Fl p Ar port_number 36.Op Fl P Ar client_principal 37.Sh DESCRIPTION 38.Nm 39runs on a client using 40.Tn NFSv4 41to handle callback requests from the NFSv4 server. 42If no 43.Nm 44is running, NFSv4 mounts will still work, but the server will never issue 45Open Delegations to the client. 46.Pp 47One callback server and one master server 48are always started. 49.Pp 50The following options are available: 51.Bl -tag -width Ds 52.It Fl p Ar port_number 53Specifies what port# the callback server should use. 54.It Fl P Ar client_principal 55Specifies the host based principal name to be used as the target for 56callbacks over RPCSEC_GSS. For KerberosV, it must be in the client's 57default keytab file. 58This client_principal should be the same one specified by the 59.Cm gssname 60argument being used by nfsv4 mounts. 61If you do not specify this argument, callbacks will still work over AUTH_SYS, 62which is what many extant servers use even for RPCSEC_GSS mounts, as of 2009. 63.El 64.Pp 65For example, 66.Dq Li "nfscbd -p 7654 -P root" 67starts the daemon to handle callbacks on port# 7654 and is using the host based 68principal root@<client-host>.<dns-domain> as the callback target. 69.Pp 70.Nm 71listens for service requests at the port 72defined by NFSV4_CBPORT in /usr/include/fs/nfs/nfs.h, unless 73.Fl p 74has been specified. 75For more information on what callbacks and Open Delegations do, see 76.%T "Network File System (NFS) Version 4 Protocol" , 77RFC3530. 78.Sh EXIT STATUS 79.Ex -std 80.Sh SEE ALSO 81.Xr nfsv4 4 , 82.Xr mount_nfs 8 83.Sh HISTORY 84First introduced with the experimental nfs client for NFSv4 support in 2009. 85