plan9-gpl/sys/man/4/nfs

.TH NFS 4
.SH NAME
nfs \- Sun network file system client
.SH SYNOPSIS
.B nfs
[
.B -DRv
]
[
.B -p
.I perm
]
[
.B -s
.I srvname
]
[
.B -u
.I passwd
.I group
]
.I addr1
[
.I addr2
]
.PP
.B aux/portmap
[
.B -R
]
.I host
.I cmd
...
.PP
.B aux/nfsmount
[
.B -R
]
.I host
.I cmd
...
.SH DESCRIPTION
.I Nfs
translates between the Sun network file system protocol (NFS)
and 9P, allowing 9P clients to mount file systems on NFS servers.
NFS servers comprise two separate services: a mount service used to
obtain the initial file handle, and a file service used to perform
actual file system operations.
The Sun port mapper service is typically used to find these two services.
If one address is given, it is taken to be the address of a port mapper service;
.I nfs
queries the port mapper to find the addresses
of the NFS mount service and file service.
If two addresses are given, the port mapper is bypassed;
.I addr1
is used as the address of the NFS mount service,
and
.I addr2
is used as the address of the file service.
.PP
The options are:
.TP
.B -D
print all 9P messages.
.TP
.B -R
print all NFS messages.
.TP
.B -v
print verbose information about session startup.
.TP
.B -p \fIperm
set the posted service file to have mode
.IR perm ,
which is assumed to be octal;
the default is
.BR 600 .
.TP
.B -s \fIsrvname
post the service as
.BI /srv/ srvname \fR;
the default is
.BI /srv/ addr1 \fR.
.TP
.B -u \fIpasswd\fR \fIgroup
translate user and group names using the 
.I passwd
and
.I group
files, which are in the traditional Unix format.
The translation is used to present names for
user and group in
.IR stat (5)
and
.I wstat
messages.
The translation is also used to
choose the user and group credentials
to present for a user.
Without this option, users and groups are presented
as decimal numbers, and everyone attaches as uid \-1
.RB ( nobody
on most Unix systems).
.PP
.I Portmap
and
.I nfsmount
are test programs to perform port mapper and NFS mount RPCs.
They
are useful mainly to help debug problems with
starting 
.I nfs
itself.
The 
.B -R
option causes them to print all RPC messages sent and received.
.PP
.I Portmap
queries a Sun RPC portmap server, which maps integer
(program, version, protocol) triples to port numbers.
Program and version are Sun RPC defined, while protocol
is typically TCP (6) or UDP (17).
The commands are:
.TP
.B null
a no-op
.TP
.B dump
print the entire map
.TP
.B set \fIprog\fP \fIvers\fP \fIproto\fP \fIport\fP
add an entry to (or replace an entry in) the map
.TP
.B unset \fIprog\fP \fIvers\fP \fIproto\fP \fIport\fP
remove an entry from the map
.TP
.B getport \fIprog\fP \fIvers\fP \fIproto\fP
look for an entry with \fIprog\fP, \fIvers\fP, \fIproto\fP
in the map, and return the corresponding port
.PD
The default command is
.BR dump .
For running NFS over UDP, there must be an entry
for the NFS v3 mount daemon (100005, 3, 17) and the
NFS v3 server itself (100003, 3, 17).  
.PP
.I Nfsmount
queries a Sun NFS mount server, which authenticates (ha!)
connections and hands out file handles naming the root of
an exported file system.  This handle is used as the basis
for a conversation with the NFS service daemon itself.
The commands are:
.TP
.B null
a no-op
.TP
.B export
dump the export table;
each line is a path followed by a list of machines or groups
allowed to mount that path
.TP
.B mnt \fIpath\fR
attempt to acquire a file handle for \fIpath\fR.
the request has user and group id 1001 and
.L gnot
as the system name.
.TP
.B umnt \fIpath\fR
notify the mount daemon that a particular path is being
unmounted by the requesting system
.TP
.B umntall
notify the mount daemon that all paths mounted by the
requesting system are being unmounted
.TP
.B dump
should also dump an export table, but typically 
does nothing
.PD
.SH EXAMPLE
We use this in our
.B /rc/bin/9fs
script to mount all the home directories served by
.IR bopp :
.IP
.EX
case bopp
	if(! test -f /srv/bopp)
		nfs -p 666 -u /lib/ndb/1127.passwd /lib/ndb/1127.group bopp
	unmount /n/bopp >[2]/dev/null
	for(i in u0 u1 u2 u3 u4 u5 u6 u7 u8 u9)
		mount -a /srv/bopp /n/bopp /$i
.EE
.SH SOURCE
.B /sys/src/cmd/nfs.c
.br
.B /sys/src/libsunrpc
.SH "SEE ALSO
.IR nfsserver (8),
.IR srv (4)
.SH BUGS
The authentication employed by NFS is laughable.
The server simply trusts the uid, gid, and group list
presented by the client.
.PP
.I Nfs
speaks only NFS version 3.
Older operating systems typically
have reasonable NFS version 2 servers
but crash when serving version 3.