1 .\" Copyright (c) 1989, 1991, 1993
2 .\" The Regents of the University of California. All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
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 .\" 3. All advertising materials mentioning features or use of this software
13 .\" must display the following acknowledgement:
14 .\" This product includes software developed by the University of
15 .\" California, Berkeley and its contributors.
16 .\" 4. Neither the name of the University nor the names of its contributors
17 .\" may be used to endorse or promote products derived from this software
18 .\" without specific prior written permission.
20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 .\" @(#)exports.5 8.3 (Berkeley) 3/29/95
40 .Nd define remote mount points for
48 file specifies remote mount points for the
50 mount protocol per the
52 server specification; see
53 .%T "Network File System Protocol Specification" ,
54 RFC1094, Appendix A and
55 .%T "NFS: Network File System Version 3 Specification" ,
59 (other than comment lines that begin with a #)
60 specifies the mount point(s) and export flags within one local server
61 filesystem for one or more hosts.
62 A long line may be split over several lines by ending all but the
63 last line with a backslash
65 A host may be specified only once for each local filesystem on the
66 server and there may be only one default entry for each server
67 filesystem that applies to all other hosts.
68 The latter exports the filesystem to the ``world'' and should
69 be used only when the filesystem contains public information.
72 the first field(s) specify the directory path(s) within a server filesystem
73 that can be mounted on by the corresponding client(s).
74 There are two forms of this specification.
75 The first is to list all mount points as absolute
76 directory paths separated by whitespace.
77 The second is to specify the pathname of the root of the filesystem
81 this form allows the host(s) to mount at any point within the filesystem,
82 including regular files if the
86 The pathnames must not have any symbolic links in them and should not have
87 any "." or ".." components.
88 Mount points for a filesystem may appear on multiple lines each with
89 different sets of hosts and export options.
91 The second component of a line specifies how the filesystem is to be
92 exported to the host set.
93 The option flags specify whether the filesystem
94 is exported read-only or read-write and how the client uid is mapped to
95 user credentials on the server.
97 Export options are specified as follows:
100 .Fl maproot No = Sy user
102 The credential of the specified user is used for remote access by root.
103 The credential includes all the groups to which the user is a member
104 on the local machine (see
106 The user may be specified by name or number.
109 .Fl maproot No = Sy user:group1:group2:...
111 The colon separated list is used to specify the precise credential
112 to be used for remote access by root.
113 The elements of the list may be either names or numbers.
114 Note that user: should be used to distinguish a credential containing
115 no groups from a complete credential for that user.
118 .Fl mapall No = Sy user
122 .Fl mapall No = Sy user:group1:group2:...
124 specifies a mapping for all client uids (including root)
125 using the same semantics as
132 in an effort to be backward compatible with older export file formats.
138 options, remote accesses by root will result in using a credential of -2:-2.
139 All other users will be mapped to their remote credential.
143 remote access by root will be mapped to that credential instead of -2:-2.
147 all users (including root) will be mapped to that credential in
152 option specifies that the Kerberos authentication server should be
153 used to authenticate and map client credentials.
154 This option requires that the kernel be built with the NFSKERB option.
155 The use of this option will prevent the kernel from compiling
156 unless calls to the appropriate Kerberos encryption routines
157 are provided in the NFS source.
161 option specifies that the filesystem should be exported read-only
162 (default read/write).
167 in an effort to be backward compatible with older export file formats.
170 exports strictly according to the spec (RFC 2054 and RFC 2055) can
174 However, this flag in itself allows r/w access to all files in
175 the filesystem, not requiring reserved ports and not remapping uids.
177 is only provided to conform to the spec, and should normally not be used.
186 .Fl mapall No = Sy nobody
193 .Fl index No = Sy file
195 option can be used to specify a file whose handle will be returned if
196 a directory is looked up using the public filehandle
198 This is to mimic the behavior of URLs.
201 option is specified, a directory filehandle will be returned as usual.
204 option only makes sense in combination with the
210 The third component of a line specifies the host set to which the line applies.
211 The set may be specified in three ways.
212 The first way is to list the host name(s) separated by white space.
213 (Standard Internet ``dot'' addresses may be used in place of names.)
214 The second way is to specify a ``netgroup'' as defined in the netgroup file (see
216 The third way is to specify an Internet subnetwork using a network and
217 network mask that is defined as the set of all hosts with addresses within
219 This latter approach requires less overhead within the
220 kernel and is recommended for cases where the export line refers to a
221 large number of clients within an administrative subnet.
223 The first two cases are specified by simply listing the name(s) separated
225 All names are checked to see if they are ``netgroup'' names
226 first and are assumed to be hostnames otherwise.
227 Using the full domain specification for a hostname can normally
228 circumvent the problem of a host that has the same name as a netgroup.
229 The third case is specified by the flag
231 .Fl network No = Sy netname
235 .Fl mask No = Sy netmask .
237 If the mask is not specified, it will default to the mask for that network
238 class (A, B or C; see
242 .Bd -literal -offset indent
243 /usr /usr/local -maproot=0:10 friends
244 /usr -maproot=daemon grumpy.cis.uoguelph.ca 131.104.48.16
245 /usr -ro -mapall=nobody
246 /u -maproot=bin: -network 131.104.48 -mask 255.255.255.0
247 /u2 -maproot=root friends
248 /u2 -alldirs -kerb -network cis-net -mask cis-mask
257 local filesystem mount points, the above example specifies the following:
261 where friends is specified in the netgroup file
262 with users mapped to their remote credentials and
263 root mapped to uid 0 and group 10.
264 It is exported read-write and the hosts in ``friends'' can mount either /usr
269 .Em grumpy.cis.uoguelph.ca
270 with users mapped to their remote credentials and
271 root mapped to the user and groups associated with ``daemon'';
272 it is exported to the rest of the world as read-only with
273 all users mapped to the user and groups associated with ``nobody''.
276 is exported to all hosts on the subnetwork
278 with root mapped to the uid for ``bin'' and with no group access.
281 is exported to the hosts in ``friends'' with root mapped to uid and groups
282 associated with ``root'';
283 it is exported to all hosts on network ``cis-net'' allowing mounts at any
284 directory within /u2 and mapping all uids to credentials for the principal
285 that is authenticated by a Kerberos ticket.
289 utility can be made to re-read the
291 file by sending it a hangup signal as follows:
292 .Bd -literal -offset indent
293 kill -s HUP `cat /var/run/mountd.pid`
300 output to see whether
302 logged any parsing errors in the
306 .Bl -tag -width /etc/exports -compact
308 the default remote mount-point file
316 The export options are tied to the local mount points in the kernel and
317 must be non-contradictory for any exported subdirectory of the local
319 It is recommended that all exported directories within the same server
320 filesystem be specified on adjacent lines going down the tree.
321 You cannot specify a hostname that is also the name of a netgroup.
322 Specifying the full domain specification for a hostname can normally
323 circumvent the problem.